Help with the nomads

[Soggius Chippius]

I just use mass horse archers (no infantry. They just end up routing anyway) and keep 3 or so shooting at the front of the enemy line while everyone else goes around behind and obliterates them front the back. Ridiculously efficient, since usually you end up with few to no casualties. Only problem is when the AI decides to be a bit clever and sends enemies in different directions. Then it calls for a bit more micromanaging, but still quite winnable.
Ironically, the very worst enemy to face is horsearchers (with foot archers a step down on the list) since they nullify your agility with their blasted arrows.
(only problem is sieging. Usually you'll have to starve them out, especially if they're stone walls/oppida, but waiting for a reinforcing enemy army is just as easy usually anyway, since you can use your horsearchers in the field)