playing as Thrace, i was stuck in a war with the much richer, much more powerful Macedon.

unlike most other factions, Thrace doesn't have much in the way of decent cavalry

Macedon was repeatedly sending full armies under a single banner at me

i managed to get a full army, plus a bit more besides. with the lesser quality troops, i surrounded the single enemy army and hit it with my main one. all i had to do was make them rout, and the entire army was annihilated because they were surrounded.