well remember Camilian roman troops are don't have that great stats exept for the Triarii. Plust you must add +7 to the attack and defence of the AI units......

My suggestion, buy some Pezetaroi (sp) mercs instead of barbarian cavalry, get on top of a mountain in the campain map, and let the AI attack u. The high groud will help u win the battle. Thats how I beat the AI of Selucia and Ptolemoi in VH/VH in EB .74 with KH.... but then again EB .74 used RTW 1.2 (and as we all know AI in 1.2 is not the AI in 1.5)