Seleucids.

Gen cav
2 Armored Elephants
3 Cataphracts
2 Companion Cavalry
3 Silver Shield Phalanx
4 Silver Shield Legions
2 Onagers
As many archers as I can

Defending:

Find a steep incline (the steepest possible, sometimes none). Infantry in front (phalanx center, legions wings set on FAW). Archers behind them a good distance. Onagers dead behind the archers. Companions on one wing, Cataphracts on the other, elephants on whichever wing I feel like (usually the one with the steepest incline I can find). Gen with Companions. Sit and wait. Burn and feather as many as I can. Usually by the time they get to the army they are ready to break. When they attack, send elephants in across their line from the side and get to smashing, call off archers, when the army routs, send cavalry to mop up.


Attacking:

If they don't have any archers, send my archers up to shoot them to bits. Send elephants in. Send cavalry in to mop up.

I played once as the Julii, but it was my first campaign (and short) so I didn't develop any solid armies/tactics.