Britannia

[Agent Miles]

I made lots of money as the Brits (VH/VH huge units). Right from the start, I took all of the spare population in Samarobriva and sent them north as peasants to upgrade Eburacum and then Deva. I then abandoned it to rebellion. This prevents early war with Gaul/Germania, who always attack this settlement. I then took Tara and demobilized part of my army there. Now I have four settlements with 2k+ population. I don't need a standing army, so I upgrade like crazy with about 2k-4k income per turn. I ship my peasants around to get all of the settlements quickly up to 6k. I also like building watchtowers so that I can see as much as possible.
I have enough cash so that each settlement can construct all of the buildings (except for the beer hall variety). I put one of each temple in the three settlements in Britain so that I can rotate my family members around to get the best of each temple. By hiring mercenaries and fighting rebels I can usually pick up a couple of retinue to raise command by 1 each as well.
In the meantime, Gaul gets into trouble with Spain/Germania/Julii. When my forces are ready, I invade. By 230, I have overrun western Gaul without any problems. My army consists of 9 Chosen Swordsmen, 6 War hounds, 3 Light chariots and one heavy chariot (all +2 experience level and +1 armor/weapons) with a 6+ star general. All of these units conspire to cause a lot of fear in any enemy force. If you wish, by periodically landing a general in Gaul you can gradually hire several Barbarian Cavalry, too. I usually have a mobile reserve of B. cav and chariots to spank rebels behind my lines. This way, I even got two generals who had the “+1 command when leading cavalry” trait. With a large war chest, my diplomats can snatch up small settlements too.
Light chariots are great missile platforms and can run down any routers. I had one unit cause over 340 casualties in one battle. Heavy chariots are great at turning flanks. I usually charge through a unit, i.e., don’t target the unit, target the opposite side of the unit. Hit them when they are disorganized.
Having won the short game, I plan on expanding my force to include the special units. I’ll crush Spain and Germania next and then take out those darn Romans.

[Seamus Fermanagh]

I made lots of money as the Brits (VH/VH huge units). Right from the start, I took all of the spare population in Samarobriva and sent them north as peasants to upgrade Eburacum and then Deva. I then abandoned it to rebellion. This prevents early war with Gaul/Germania, who always attack this settlement. I then took Tara and demobilized part of my army there. Now I have four settlements with 2k+ population. I don't need a standing army, so I upgrade like crazy with about 2k-4k income per turn. I ship my peasants around to get all of the settlements quickly up to 6k. I also like building watchtowers so that I can see as much as possible.
I have enough cash so that each settlement can construct all of the buildings (except for the beer hall variety). I put one of each temple in the three settlements in Britain so that I can rotate my family members around to get the best of each temple. By hiring mercenaries and fighting rebels I can usually pick up a couple of retinue to raise command by 1 each as well.
In the meantime, Gaul gets into trouble with Spain/Germania/Julii. When my forces are ready, I invade. By 230, I have overrun western Gaul without any problems. My army consists of 9 Chosen Swordsmen, 6 War hounds, 3 Light chariots and one heavy chariot (all +2 experience level and +1 armor/weapons) with a 6+ star general. All of these units conspire to cause a lot of fear in any enemy force. If you wish, by periodically landing a general in Gaul you can gradually hire several Barbarian Cavalry, too. I usually have a mobile reserve of B. cav and chariots to spank rebels behind my lines. This way, I even got two generals who had the “+1 command when leading cavalry” trait. With a large war chest, my diplomats can snatch up small settlements too.
Light chariots are great missile platforms and can run down any routers. I had one unit cause over 340 casualties in one battle. Heavy chariots are great at turning flanks. I usually charge through a unit, i.e., don’t target the unit, target the opposite side of the unit. Hit them when they are disorganized.
Having won the short game, I plan on expanding my force to include the special units. I’ll crush Spain and Germania next and then take out those darn Romans.

Don't expect too much from the dogs or the heavy chariots versus Roman Legionaires. Your light chariots will still work, but almost all of the romans are armored as well as your chosen sword, so your kill ratios will drop. Head hurlers are quite effective though -- unrealistic buggers as they are -- since you have javelins that are just as hard hitting as those of a Praetorian, but carry 6 to their 2. Your hurlers will get torn up by his archers though, so be careful.

[Agent Miles]

So far, the AI won’t put together a full stack. I see several groups of 12 or fewer units. With nine Chosen Swordsmen, I can just overwhelm their line while flanking with the chariots. I chose hounds, chariots and CS because they are easy to replace in most settlements. I do have some head hurlers now for those armored units. Gaul is gone. Spain, Germania and the Julii are down to two or three settlements each. Thanks for the tips.