From what I've read it certainly sounds like you're on VH for battle difficulty. No matter how AP falcata (pl?) are, they only halve armour values so you should still have one mighty hunk of armour between you and him. And since I conquered spain in the late Camillan and early Polybian era with ease despite hordes of Qarthadastim caetrati and scutari, it seems a bit incredible that caetrati can eat up Augustans so.