komisches: Sure. Here's what I generally do:
On Attack:
If I'm trying to take someone else's town, i go with a mix of cavalry and artillery. It moves pretty quick, and you can get some fast attack combos happening if you do it right.
If I'm raiding another settlement, I use infantry and artillery. Four infantry and an artillery piece take quite a while to kill, even if they're getting charged by the cavalry. Raiding is all about turns spent in combat. The longer you spend in combat, the more you will steal (or eventually, destroy the whole damn thing).
On Defence:
Defence i'll usually have more cavalry/artillery, but still some infantry sitting around if I need them. If you're defending against a raid you'll want cavalry/artillery to move against the enemy quickest.
Bonuses:
Cavalry get an attack bonus from charging, ie moving into the square adjacent to them and then firing, all in one go.
If you mix different troop types (inf, cav, arty) in your attacks, you also get an attack bonus.
The ultimate bonus balance is the 3 unit types, a charge and a flank attack.
Also, there seems to be some hidden rule about the enemy retreating. It seems to be something to do with the strength of your units on the field as compared to your enemy's.
ok so what i don't get is that when i have a few armies defending a city it only uses one of them. is that how it really is or is there a way to use all leaders stationed in a city to defend it against an attack?