What are the advantages & weaknesses of Japanese against Roman warfare?

[nameless]

This is silly.

The Japanese in this case we're talking about is 16th century.

The Roman army in question is 2-3rd century.

No matter what you look at the Romans are clearly outclassed here in terms of fighting techniques, technology, etc. I mean of course the samurai equipment will be superior to anything an Imperial Legionare carries.

Even if we're to take the Byzantine Empire it's peak was about 12-14th century and they evolved from how the Romans fight at that time.

For arguments sake and for the thread

A typical Roman army would consist of legions plus auxilary units from whatever local region is possible. The vast majority will of course be of the heavy infantry type which carries pilum, shield, and gladius. And again, Roman legions fight as a single unit and not individually. Whereas a gallic army could bring in 2-3 warriors to a front line a Roman army could bring in 5-6 guys to a front line. Roman armies are deadly in close quarter combats because the gladius does not need a lot of space to fight in. Plus the Legionaries would have tons of experience from fighting the dozens of various tribes they've had over the years. Add to the fact that they are professional soldiers as well and are extremely disciplined.

Then you add in their auxillary units which could include light infantry or cavalry for support.

A japanese army I do not know much but I'm pretty sure that the majority of them would be ashigaru soldiers whose equipment aren't as good as a samurai's which make up a small core.

So really the Roman army wouldn't exactly be facing 10,000 samurai would they?

[Nelson]

This is silly.

The Japanese in this case we're talking about is 16th century.

The Roman army in question is 2-3rd century.

No matter what you look at the Romans are clearly outclassed here in terms of fighting techniques, technology, etc. I mean of course the samurai equipment will be superior to anything an Imperial Legionare carries.

Even if we're to take the Byzantine Empire it's peak was about 12-14th century and they evolved from how the Romans fight at that time.

Using this logic, 18th century North American Apaches have an advantage over Roman legions and Sengoku samurai armies as well!

[nameless]

Using this logic, 18th century North American Apaches have an advantage over Roman legions and Sengoku samurai armies as well!

While my knowledge of North American indians is weak I do know that in comparisons the New World natives didn't advance the same way as the Old world (I would include Japan as Old world as well).

That and one of the main reasons the 18th century Musket armies were able to conquer the new world was through diseases so I would say 18th Century Apaches would give any Japanese/Roman army a good beating as they do not fight open warfare but hit and run which the Romans always had difficulty fighting against.

That and no one seems to answer my question whether a Japanese army would actually comprise mainly of samurai.

[Kagemusha]

nameless, i think i answered that one already in my post on last page. Nelson, i am bit reluctant to even get into this argument as to me its absurd, but please tell me how for example the legion can protect its flanks and rear when mounted samurai were using stirrups, which enabled them to basically stand on horseback fighting with variety of weapons, while during the times of Rome such thing was not even discovered?

[Shibumi]

Who would win, Super Space Oranges vs Mutated Apples?

Clearly you people are putting your minds to use.

[Koga No Goshi]

I really hate these comparisons. It's probably better to compare different aspects of the army; logistics, for example. The Romans likely outclassed the Japanese in their respective time periods.

That's rather stacking the deck considering Rome owned a huge portion of the ancient world. That's like saying let's see who had a better long-distance travel system, the Mongol Empire or Japan.

[Shibumi]

That's rather stacking the deck considering Rome owned a huge portion of the ancient world. That's like saying let's see who had a better long-distance travel system, the Mongol Empire or Japan.

I think he just pointed out the futility of the topic, like I did.

[Rothe]

I'd say you have to assume equal numbers with typical army composition of the time.

Not every soldier in a Japanese army of that time would have a katana. Think about this.
Some also seem to assume that everyone with a katana is Miamoto Musashi and everyone with a gladius & shield is just "some guy who picked it up". Not all katanas are masterfully smithed. Some are just decent swords comparable to gladius et al.

The problem is that perceptions are colored to see Japanese as some gods of warfare and romans as the grunts. In real terms, I think they were both well trained and disciplined. The looks don't matter in the fight unless the enemy is scared because they are undisciplined. Romans had their tricks too (fire and dogs etc. etc.)

Seriously. Think in equal terms. Romans had a more even army consistency. They all had pretty standardized equipment. In a battle with even numbers, a lot of the Japanese army would be spear ashigaru and so on.

If you take the best japanese army that was fielded, then maybe you'll get a lot of samurai, but then you gotta take also the elite Roman troops into that battle.

With typical consistency of majority of lower class troops, romans would take it in my mind. They had unified tactics, equipment and the japanese yari troops were really peasants with some training. Romans were professional troops.'

Elite vs. Elite is more even I guess. Pure samurai troops vs. Roman elites is still not a clear win for Japanese IMO. I call it quite even, or even slightly favoring the romans still.

[Vladimir]

That's rather stacking the deck considering Rome owned a huge portion of the ancient world. That's like saying let's see who had a better long-distance travel system, the Mongol Empire or Japan.

The statement was made within the context of the thread; specifically the OP.

[Marshall Louis-Nicolas Davout]

No,Even still,Japanese infantry were still stubborn and strong.Bring in Matchlock Yari ashaguri,then see how your arguements turn to lies.Japanese armies were still superiror.Put them in front of a medeival 15th century battle,and we're even sided here.

[Rothe]

No,Even still,Japanese infantry were still stubborn and strong.Bring in Matchlock Yari ashaguri,then see how your arguements turn to lies.Japanese armies were still superiror.Put them in front of a medeival 15th century battle,and we're even sided here.

First post should be edited to leave guns out. No gunpowder weapons for the comparison, since it makes little sense to try to do it that way.

[Kagemusha]

First post should be edited to leave guns out. No gunpowder weapons for the comparison, since it makes little sense to try to do it that way.

Did you read my posts at all? Maybe you would like to address my poin of concerns? Let us see:

Mounted forces, Japanese mounted warriors have a small advantage called stirrups, so they have a serious advantage fighting melee from horse back. Impossible for Romans to win on flanks.

footmen, Japanese combined weapon squads consisting of front of Ashigaru armed with nagae yari pike´s ranging from 5 to 7 meters long, supported by bowmen with yumi, japanese longbow shooting at point blank range to Legionaries, backed up with more heavily armed and armored unmounted samurai.

Armor, for romans mostly lorica hamata and to a lesser extent lorica segmentata and squamata. For Japanese lamellar armour with surface of smaller or larger steel plates. Most of Japanese weapons were aimed to puncture, thus iron chainmail, or partial iron plate would not be much protection against, while 1200 years advantage in metallurgy points in favour of Japanese.

One knows that legions were able to defeat pikemen, aka hellenistic phalangites. The reason for it, more tactically flexible tactics and ability to win the fight at flanks. While hellenistic phalangites deployed in huge pike phalanxes, Japanese depolyed their pikes in only few line deep formations. If we accept the fact that Romans cant win the mounted battle on flanks. How can they defeat the Japanese pikes head on with their large shield, pilum and short sword, when the reach advantage and missile advantage is towards the Japanese, while they can be freely flanked by the Japanese who had lot more flexible organisation, like ive shown in my previous post already. To me your earlier comment that Japanese are thought as war Gods and Romans mere grunts is uncalled for.

Had the opposing forces be contemporary European army against Japanese.I would favour the European, because their advantage in cavalry and artillery. Would the forces been Japanese army of 1st-3rd century AD against Legions.I would be clearly in favour of Legions, but to claim that army with 1200 older technology, armour and weapons would defeat the later one, is nothing else then hybris to me.

[Vladimir]

I can negate your cavalry argument by reminding you that the Romans relied on their allies, or mercenaries, to provide cavalry support. I know the stirrup didn't come around until the 4th century AD or so they had the potential of acquiring better cavalry. The cavalry archers used by the Eastern Roman Empire would cause a lot of grief.

Again I suggest that the Romans would win an extended campaign due to their organization, discipline, and logistics.

[Kagemusha]

still the same advantages in metallurgy would be in place. Iron,stone or bone arrow heads are bit weak compared to steel. If you are referring to steppe nomads of the time.Same goes with armour. So can you tell me what 300AD mounted warriors were equal or stronger then 1500 AD mounted samurai? Remember Ashigaru had no business being at horseback, so the mounted Japanese element were all elite.

[andrewt]

I can negate your cavalry argument by reminding you that the Romans relied on their allies, or mercenaries, to provide cavalry support. I know the stirrup didn't come around until the 4th century AD or so they had the potential of acquiring better cavalry. The cavalry archers used by the Eastern Roman Empire would cause a lot of grief.

Again I suggest that the Romans would win an extended campaign due to their organization, discipline, and logistics.

Rome wasn't known for their cavalry nor archery. They pretty much suck at it. Mercenaries would be no match for the Japanese.

If we're talking about the Eastern Roman Empire, they're more a contemporary as they fell 200 years before the Sengoku Jidai. The Western Roman Empire army that we're being asked to compare is over 1500 years older. I think some people are assuming that there are 0 significant advances in metallurgy during all those years.

I don't think the Roman gladius can even compare to a modern steak knife.

[Marshall Louis-Nicolas Davout]

[QUOTE=andrewt;2053356809]Rome wasn't known for their cavalry nor archery. They pretty much suck at it. Mercenaries would be no match for the Japanese.

If we're talking about the Eastern Roman Empire, they're more a contemporary as they fell 200 years before the Sengoku Jidai. The Western Roman Empire army that we're being asked to compare is over 1500 years older. I think some people are assuming that there are 0 significant advances in metallurgy during all those years.

I don't think the Roman gladius can even compare to a modern steak knife.[/QUOTe


Hmm I can agree.The Japanese had clever leaders,something which the romans lacked.Takeda Shingen,Oda Nobunaga,Uesgai Kenshin,Date Massamue.

What they're forgetting is the fact that that Japanerse armies had more units than ever.Tachi Samurai,There were a wide a amount of Samurai and they seem to underestimate that yes pretty much,cavarly was elite.Katana Ronin and Yari Ronin,Ashaguri Nagainta and there were a wide amount of monk warriors.Sure the Romans would have flung javlens,but the samurai dont fight with shields.They would have charged no matter what.And the fact everyone seems to forget,that becoming a samurai,let alone a yari ashaguri took years of pratice.Or months.

Samurai were higly skilled swordsmen.In fac it is strange to think that european armies fought with shields,and eastern armies fought with shields,but the Japanese were the only people to never fight with a shield!Think of it,all the people of the world have some sort of shield. Even still they would have been highly skilled in how to use them,and they would have slit a roman straight before had a chance,think of no-dachi samurai immideatly plungining their swords into a samurai's throat.You could see it that way

[Nelson]

The Japanese had clever leaders,something which the romans lacked.

Scipio, Sula, Marius, Caesar, Germanicus, Pompey, Agripa. Yeah, those Roman commanders were bums. The whole lot of 'em...

[Peasant Phill]

Think of it,all the people of the world have some sort of shield. Even still they would have been highly skilled in how to use them,and they would have slit a roman straight before had a chance,think of no-dachi samurai immideatly plungining their swords into a samurai's throat.You could see it that way

I've always wondered why the use of a shield never caught on in Japan ( was there a time shields were in use?). One would imagine that shields had their uses against two handed swords, spears and archers of course. I somehow doubt a no-dachi being able to easily overpower a legionnaire in formation, a shield wall is very effective. That's of course not to say that the battle would be very different on the flanks and not taking guns into account.

[Arjos]

I know of some shields in the Ryukyu islands, but nothing else...
Anyway contemporary Europe almost didn't use shields either...
Why a shieldless samurai is different from a gothic knight? And I mean the first one without a shield, is it something out of this world? :D

[faker01]

Rome wasn't known for their cavalry nor archery. They pretty much suck at it. Mercenaries would be no match for the Japanese.

When the cacalry from rome would fall, they would have no defense against japanese cavalry. (rome had big problems with cavalry, so they changged their equipments)

[NightwindKing]

lol odd place to introduce myself I know, but I thought I'd add-in my two cents (hi, Im new ;-)

Historians tend to agree on Rome's effectiveness/power/strength for a number of reasons...one being their hierarchy/social structure and communications system (roads, prefects, etc...) and another being their cohesive and cookie-cutter military. Not because a perfectly uniform military is best, but because it was best in their time period, for who they fought against.

The Greeks had a similar success. Alexander's forces were famous for their strong cohesian and 'stand together' attitude, which was what allowed them to beat the old-world Persian hordes under Darius II (or was it I?). When the tactics, equipment, and skill of two armies comes down purely to who is more orderly and 'in control', the more unified force will almost always win. It's simple logic.

That said, Rome won its battles primarily because its commanders (when they weren't incompetent morons, obviously) were able to intelligently use their strengths to their advantage. One of the primary strengths was the unification and cohesian of its military forces.

However, as has been said, just because something is uniform doesn't make it great...the cavalry, for example, which sucked. And was uniformly sucky.

The Roman army was designed to be a powerhouse and anvil to swiftly stomp-out rebellion and fractured tribes by virtue of its unification, advanced (for the time) technology, and common tactics. It was made to fight in open, massed battles of two or more large massed forces fighting head-to-head. Rome historically did poorly in defending against ambushes (most armies do, I suppose).

That said, the Japanese army (as an umbrella term) was designed for mountainous forest warfare. The large open massed battles in fields or hills were not nearly as common as ambushes, mountain seiges, and skirmishes. It's why there are so few 'legendary' Japanese battles known outside of Japan...westerners think of amazing battles like Thermopylae (however you spell it), Agincourt, D-Day, etc...whereas for the Daimyo, a larger battle was more costly and, in all likelyhood not as 'worth it' if the gain could be had with lesser forces. Book of Five Rings, for example, makes a huge point that the greatest commander is the one who wins without fighting any battles (echoed in The Art of War).
Samurai were, on a whole, well-trained swordsman. They were as accustomed to fighting in their armor, with their weapons, as the Legionnaires were. The Samurai, though, were used to fighting one-to-one, looking for personal honor. The samurai 'style' of warfare was one of calling-out your opponent, stepping around your allies, and dueling till one was dead, then moving on. HUGE difference from the Roman 'lock shields and stand' model.
So, it would all depend on the type of battle, the intelligence of the commander, etc...

Everyone can agree, I think, that in one-to-one a generic, well-trained armored Samurai would crush a legionnaire handily.
In pitched battle? Since samurai armies were generally largely ashigaru (which really isn't a unit type anyway, just a rank), spear-armed or bow-armed peasants...no doubt well-versed in their weapon, but not hardened lifestyle warriors. I'd say in a mountainous-terrain battle, in Japan, the Japanese would win. They'd know how to get around even the tough Roman front. In an open field in capernum, Rome would likely win. They'd have the experience of such open battles that not even the best Japanese commander would have much of.

[NightwindKing]

And all of that to, of course, not reply to the actual scenarios! Sorry man.

Reenactment of the Battle of Teutoburg Forest. This time, the Japanese are the ones who will carry out the ambush. Rome has three legions (Legio XVII, Legio XVIII, and Legio XIX), six cohorts of auxiliary troops (non-citizens or allied troops) and three squadrons of cavalry.
This is easy. The Japanese would CRUSH the Romans. Varus was an arrogant idiot. His forces were tired, in foreign territory, hungry tired and wet. Plus they were spread-out and mixed with civilians. The Japanese ambushing would be alert and ready, not to mention that they're in their 'native' environment (hilly forests). No chance the Romans would win.

2. A Siege Battle. Let's just say Rome made a time machine to lay waste on Japan. They will be assaulting Himeji Castle(http://en.wikipedia.org/wiki/Himeji_...Design_details). Attacking contingent will be 3 legion strong complete with onagers and ballistae.
>>>What will be the ideal number of Japanese units to successfully defend the castle? And what units will YOU field?Can the Romans use their siege engines to full effect?
The Japanese COULD win this. Would depend on the commander. With 18,000 attacking Romans I guess I'd go for a cavalary force of 8,000, a yumi samurai force of 3,000 and a sword-armed contingent of 2,000. I doubt it would be feasible, though for a single clan to muster that kind of strength, and all in samurai. All in all, though, I'd say the mounted contingent is the most important. The Romans could shoot their ballistae and onagers all they liked but there's not much wall of Himeji to destroy. And it would depend on if they were trying to capture the castle (blow walls, insert troops ;-) or destroy it, in which case a couple flaming pitch barrels would work.
If the Romans tried to burn-out the Japanese defenders, they'd win. The Japanese would be forced to sally and their cavalry would have to support the attack, leading to them breaking against the Roman shieldwalls. If, however, Rome attempted to assault the castle and scale the walls, I think the Japanese would be able to defeat them...would depend on flanking them with the cavalry while the legions were climbing/massed near the wall.

3. A Field Battle. It's purely a measure of tactical prowess. Provided we copy the battle specs of the Battle of Zama. However, it would be the Japanese instead of Carthage. Rome, led by Scipio, is 34,000 infantry and 6,000 cavalry strong(including Numidians), Japanese will have 45,000 infantry, 6,000 cavalry and 80 war elephants with Carthaginians to man them.
The Japanese have no experience using war elephants. They've fought AGAINST them, but they would be at worst a liability and at best a wild card. A smart So-Daisho would keep them in the rear.
My guess is the Samurai cavalry would crush the Roman cavalry early-on and move to attack their flanks. The Japanese would charge supported with spearmen and bowmen behind, after launching a couple volleys every dozen yards.
The Romans would slowly advance a shield wall, leaving their archers positioned statically. Upon having the Samurai charge their flank the shield wall would pull back, archers drawing fire, at which point the central Ashigaru would charge, supported by massed bow fire. When the Romans pressed in the Samurai on the flanks would squeeze.
At that point it would be a question of whether the Japanese could break the shield wall. If the cavalry were quick and smart enough, they might be able to lead the edge and get around, at which point the legions would be forced to draw back or collapse, giving the Ashigaru an opening. Still, my guess is a smart Roman commander with morale-high troops would win, narrowly. Remember the Romans would be willing to retreat, while Bushido demands that you kill your enemy or die (I'm generalizing here). My guess is the Romans might tire, slipping up and allowing the Samurai to pour-in to the center, but if their morale held the Romans would win.

[Peasant Phill]

Hello NightWindKing, A nice introduction. I'll leave it to others to go further into your arguments.

I think the monastary here would be of great interest to you.

[Marshall Louis-Nicolas Davout]

lol odd place to introduce myself I know, but I thought I'd add-in my two cents (hi, Im new ;-)

Historians tend to agree on Rome's effectiveness/power/strength for a number of reasons...one being their hierarchy/social structure and communications system (roads, prefects, etc...) and another being their cohesive and cookie-cutter military. Not because a perfectly uniform military is best, but because it was best in their time period, for who they fought against.

The Greeks had a similar success. Alexander's forces were famous for their strong cohesian and 'stand together' attitude, which was what allowed them to beat the old-world Persian hordes under Darius II (or was it I?). When the tactics, equipment, and skill of two armies comes down purely to who is more orderly and 'in control', the more unified force will almost always win. It's simple logic.

That said, Rome won its battles primarily because its commanders (when they weren't incompetent morons, obviously) were able to intelligently use their strengths to their advantage. One of the primary strengths was the unification and cohesian of its military forces.

However, as has been said, just because something is uniform doesn't make it great...the cavalry, for example, which sucked. And was uniformly sucky.

The Roman army was designed to be a powerhouse and anvil to swiftly stomp-out rebellion and fractured tribes by virtue of its unification, advanced (for the time) technology, and common tactics. It was made to fight in open, massed battles of two or more large massed forces fighting head-to-head. Rome historically did poorly in defending against ambushes (most armies do, I suppose).

That said, the Japanese army (as an umbrella term) was designed for mountainous forest warfare. The large open massed battles in fields or hills were not nearly as common as ambushes, mountain seiges, and skirmishes. It's why there are so few 'legendary' Japanese battles known outside of Japan...westerners think of amazing battles like Thermopylae (however you spell it), Agincourt, D-Day, etc...whereas for the Daimyo, a larger battle was more costly and, in all likelyhood not as 'worth it' if the gain could be had with lesser forces. Book of Five Rings, for example, makes a huge point that the greatest commander is the one who wins without fighting any battles (echoed in The Art of War).
Samurai were, on a whole, well-trained swordsman. They were as accustomed to fighting in their armor, with their weapons, as the Legionnaires were. The Samurai, though, were used to fighting one-to-one, looking for personal honor. The samurai 'style' of warfare was one of calling-out your opponent, stepping around your allies, and dueling till one was dead, then moving on. HUGE difference from the Roman 'lock shields and stand' model.
So, it would all depend on the type of battle, the intelligence of the commander, etc...

Everyone can agree, I think, that in one-to-one a generic, well-trained armored Samurai would crush a legionnaire handily.
In pitched battle? Since samurai armies were generally largely ashigaru (which really isn't a unit type anyway, just a rank), spear-armed or bow-armed peasants...no doubt well-versed in their weapon, but not hardened lifestyle warriors. I'd say in a mountainous-terrain battle, in Japan, the Japanese would win. They'd know how to get around even the tough Roman front. In an open field in capernum, Rome would likely win. They'd have the experience of such open battles that not even the best Japanese commander would have much of.

No,I disagree.Japanese armies did have a lot peasntry in them.But they did have Nagainta Samurai,they had a huge variety of units.I don't believe that the Japanese would lose that easily.The 4th battle of Kaminjakwa was fought on land.Matchlock were bought in as well.Despite the romans being led as a powerhouse army,they would have lacked leaders,effctive enough.Japanese armies consisted of what theri Damiyo chose.Everything was up to him,he ran the clan,so army formations would be different.Oda would have matchlock,ashaguri and others.Takeda would have cavarly,samurai,mostly peasntry and archers.

Each Damyio in Japan had a different way of organized their armies.Like I said,Samurai are highly trained swordsmen.Bow Ashaguri would have still been firing,and bring in matchlock,they would shatter a roman sheild wall.Bring thousands of samurai agsint a 1000 roman wall shield,lets see.It depends on the Leaders.Takeda would have seen the obvious advantage and Kenshin would have thought a 100 times to see how they would defeat their enemy.The Best Japanese commanders would have experince.I dont think they're fools to let a battle go on like that.

[Marshall Louis-Nicolas Davout]

[QUOTE=Peasant Phill;2053357021]I've always wondered why the use of a shield never caught on in Japan ( was there a time shields were in use?). One would imagine that shields had their uses against two handed swords, spears and archers of course. I somehow doubt a no-dachi being able to easily overpower a legionnaire in formation, a shield wall is very effective. That's of course not to say that the battle would be very different on the flanks and not taking guns into account.[/QUOT

hmm,I think they would have been in use,only in the early periods of history,then it would have been abandoned.But what would happen if a samurai had two swords?
?

[Peasant Phill]

...But what would happen if a samurai had two swords?

I think you would have a hard time finding more than a few isolated cases of people dual wielding swords.

[NightwindKing]

No,I disagree.Japanese armies did have a lot peasntry in them.But they did have Nagainta Samurai,they had a huge variety of units.I don't believe that the Japanese would lose that easily.The 4th battle of Kaminjakwa was fought on land.Matchlock were bought in as well.Despite the romans being led as a powerhouse army,they would have lacked leaders,effctive enough.Japanese armies consisted of what theri Damiyo chose.Everything was up to him,he ran the clan,so army formations would be different.Oda would have matchlock,ashaguri and others.Takeda would have cavarly,samurai,mostly peasntry and archers.

Each Damyio in Japan had a different way of organized their armies.Like I said,Samurai are highly trained swordsmen.Bow Ashaguri would have still been firing,and bring in matchlock,they would shatter a roman sheild wall.Bring thousands of samurai agsint a 1000 roman wall shield,lets see.It depends on the Leaders.Takeda would have seen the obvious advantage and Kenshin would have thought a 100 times to see how they would defeat their enemy.The Best Japanese commanders would have experince.I dont think they're fools to let a battle go on like that.

Hi Takeda!

I hear what you're saying, and I agree that with the right leader(s), Japan could win.
My caveat was that the Roman force would have to have an intelligent, competent general, or the entire argument is moot (since their sucky generals REALLY sucked lol).
And the Japanese had a huge variety of units but that's my point...their variety means they never had an overwhelming number of any ONE thing. Yes they had a good number of awesome naginata samurai...they also had a good number of farmers with sticks. And samurai with bows. And farmers with bows. And merchants with cannons. And so on. A mixed force is useful, yes, in the hands of a skilled strategist, but ignoring gunpowder units, there's really only one way to break a tight, courageous shield wall like that of the Romans, and that's to either get around it (which I mentioned...naginata cavalry, for example), or to break through it. And my guess is that Samurai, unused to fighting against huge legion shields, would have a hard time breaking the lines unless the Romans slipped-up somehow.
I mean, in the end it comes down to who makes the first mistake: does the Roman commander falter and break the line or allow himself to be flanked? Or does the Japanese commander throw peasant troops at a hearty shield wall and try and wait-out the enemy? I mean, you can't walk through a shield wall...hence why it's called a wall. So someone's gotta give.

[NightwindKing]

I think you would have a hard time finding more than a few isolated cases of people dual wielding swords.

The real awesomeness begins when they wield war fans! :-)

[feelotraveller]

Hm.

To my mind the Japanese would take it easily. Why? Bows. (The better horsemen would also be important but perhaps not decisive from the start.) Those arrows would be penetrating the Roman shields. The mounted samurai would be devastating but the bows would be repeatedly decimating the Romans. This would force the Romans to charge, adding to the disruption of cohesion caused by archer fire. A (even slightly) disrupted Roman formation would be made mincemeat of by katanas charging from behind an spear frontline whilst mounted samurai mopped up the Roman archers, cavalry and leadership.

Oh, and shields weren't used by the samurai as the katana was used as a shield.

[NightwindKing]

Hm.

To my mind the Japanese would take it easily. Why? Bows. (The better horsemen would also be important but perhaps not decisive from the start.) Those arrows would be penetrating the Roman shields. The mounted samurai would be devastating but the bows would be repeatedly decimating the Romans. This would force the Romans to charge, adding to the disruption of cohesion caused by archer fire. A (even slightly) disrupted Roman formation would be made mincemeat of by katanas charging from behind an spear frontline whilst mounted samurai mopped up the Roman archers, cavalry and leadership.

Oh, and shields weren't used by the samurai as the katana was used as a shield.

Definitely. Japanese yumi bows have a much greater range and strength compared to Roman ones. I guess I just don't know enough about the composition of legionnaire shields, but my guess would be they're pretty thick, and I doubt that if a yumi arrow couldn't penetrate lacquer armor, it couldn't penetrate a tower shield. Just a guess. Assuming they couldn't, I don't think Japanese bows would help break a shield wall any more than charging samurai would: still comes down to the Romans' resolve.
On the other hand, if they COULD penetrate the shields...yeah the Romans are screwed. Their style of warfare is based on passive-aggression for at least the start of the battle. The Japanese speed would overwhelm them once their shieldwall broke.