OK, let's kick this off. Has anyone done these yet?
Armenia - Early
Armenia is in a difficult position in the beginning of the game. It only has one province with not a great income. It has no trading goods, so it can't just try to be a trading power. And it's got three rich, powerful, and entrenched enemies surrounding it. Armenia has some very nice units available to it, with low building requirements, but they are expensive, so you are have to going to keep a close eye on the money and do much with little. Seems hopeless, and yet, the situation is not as bad as it looks, and Armenia is in good shape to take advantage of its Muslim enemies. You are a sword power surrounded by spear powers. You have decent cavalry available to you. You will want to play defensively or pseudo-defensively; you will need to attack often, but you want the enemy to attack you. And finally, you will often be outnumbered 3:1 or more. In many ways, you are the Byzantines with a much worse starting position; I don't know how Armenian infantry compares to Byzantine infantry, but you can use them in similar ways.
Starting out.
First off, you can't rush with the Armenians. You have only a few troops - a couple groups of spearmen, horse archers, and your king. And if you rush anyone, someone will take lesser armenia and you'll be done. Luckily, your king is a decent 4-star general, and you'll have to use him. But not yet.
You will always have to keep an eye on your homeland; if you lose lesser armenia early on, you will lose the game. It will be the only place you can raise armenian infantry for a while, and you need armenian infantry.
First turn, put up a watch tower, then build an armory. Armenian infantry are pretty good, but a little armor can only help, and you need all the help you can get. You can build one unit of armenian infantry for defense, but you don't have to; no one should bother you yet. Once the armory is complete, build a horse breeder and build 4 armenian infantry. By the time you have these, you should be just about losing money just standing still. Once you have the horse breeder, build two didebuls and get a port going.
You now have the beginnings of an army. And you're bleeding money like no tomorrow. You need to get some money. First stop: the Egyptians. Set to build another armenian infantry and move three armenian infantry, two didebuls, and your king (and the horse archers if you are so inclined) into Antioch. The army there will likely be 4 units of nubian spearmen, 2-4 saharan cavalry, and their king. They will likely outnumber you slightly. Your armenian infantry should be able to handle it, as long as they don't get separated too much and are careful to avoid attacking uphill. If you can get to them in the woods, even better; let the armenian infantry handle everything, as they are deadly to just about anything in woods.
The Egyptians will organize a counterattack a couple turns later. Fend it off in similar fashion, hiding in the woods if necessary. The egyptians will soon sue for peace; accept. Maintain the same garrison there of at least two didebuls and two armenian infantry there.
But we're still pretty short on money. And we have a powerful neighbor to our north. So next up, the Turks. You'll need to save up at least 4 armenian infantry, and preferably 3-4 didebuls for the next piece. Then send them into Edessa. The turks are different from the egyptians, in that they have many horse archers and foot archers. Your didebuls can take care of the foot archers without too much trouble, but be careful of the horse archer types; they are fast and though your didebuls can take them with ease if they catch them, they aren't likely to without help. They can at least keep them busy while your infantry destroy their middle.
Then a powerful counterattack from the turks. Usually with lots of bows. Choose a high location far from their starting position, in woods if possible, and try to have at least 4+4 waiting for them again, + the prince general. Even though you will probably be outnumbered 3:1, they will be mostly spears and bows and you can handle that, right?
Take a break and build a ship. The Egyptians are dangerous; they're still smarting from the beating you gave them last time and are massing on your southern border, nursing old grievances. And they have ships, and nearly all their provinces touch the water. They can be completely spread out, then all of a sudden dump a large invasion force right into your lap. A naval presence will be needed to keep them out.
Then, once your defenses are shored up, you have a choice: start taking the now-lightly-defended turk lands, or try to get some trade income (from Antioch). You probably can't do both. If you keep at the turks, you probably won't get far until you see the Egyptians on your southern border again. Try just to keep them off until you defeat the turks; it's tempting, especially with those rich coastal provinces, but you'll be exposed to both further egyptian agression and spread along the turks. A bad situation. You want to expand in the north, where it's still rich enough and you aren't exposed to the sea and the egyptian navy.
For the most part, the Byzantines will stay out of your way at first. But, at some point, they are going to get worried and harass your left flank. So as you expand, expand slowly and carefully. Usually 2 AI + 2 DB (armenian infantry + didebuls) can take care of either a cavalry or spear army. For the Byzantines, you might finally want to invest in a naphtha catapult and a couple archers. They are a special kind of trouble, because they have much the same unit roster you do, maybe even better. Your armenian infantry has no special advantages against byzantine infantry, though it's decent against the Kats, especially if you can hide out in the woods and make them come to you. And you may see cases where you'll attack the turks, and the Byz will come in with some huge army, the turks will withdraw, and they'll get the province instead (annoying!). But the byz aren't as strong as they look; they tend to build a lot of cheap troops, which your AI can take easily. So when they finally do start leaning on you, you'll be able to take them.
Once you have pacified the turks, you will want to turn your attention to the egyptians. You don't want to spend too much time on one enemy vs. the other; if you spend too much time on the turks, the egyptians will get too powerful, and vice versa. You want to keep each time, as it builds, wasting their troops on a large attack that you will brush off with deft ease, leaving them devastated and out of your way while you focus on their enemy (that you devastated a couple turns ago).
I haven't said much about archers and other siege artillery. This is because you'll probably on several times have to hide in the woods, and archers just don't help much there. You don't get anything better than vanilla archers until late anyways. You will want to build mostly ArmInf and some cav, mostly to deal with archers on the open field. You'll need to build some additional swordsmiths to build ArmInf as well; Didebuls only require a horse breeder, which most of the provinces you take will already have.
Once you get there, it's pretty straightforward. The ArmInf can even take on the mongols, if they get armored and valoured up a little. You will need to move quick, your units, like the byz, are better than everyone else at first, but don't improve, while eventually everyone's else troops (especially the catholics) will catch up. I don't even think you get halberdiers as the armenians. And while the didebuls do improve at high, they also require more building requirements: a spear guild + horse guild vs. just a horse breeder.
SPECIAL UNITS
Armenians get three special units AFAIK:
- Armenian infantry. Excellent all-around unit that acts like a sword unit, but is also fairly decent repulsing cavalry. They are relatively cheap to acquire, but have a high maintenance cost compared to other infantry.
- Didebuls. There are early and high didebuls. The early didebuls are roughly comparable to the Armenian Heavy Cavalry in normal play, but only require a horse breeder. The high didebuls are even better, but require a spearmaker's guild and horse breeder's guild. Don't forget this, or suddenly you may find yourself unable to train any cavalry! Like the armenian infantry, they are relatively cheap, but with high maintenance.
- Naxarars. This is basically a 20-man Didebul. You should never train these; these are in there as a royal bodyguard which doesn't have as high maintenance cost. Your king and princes will be naxarars.
