I can't seem to be able to beat those Parthians.
I've tried to counter the enemy Cataphract charge with putting my legionaries it tight formations on guard mode, or two lines. I chase the horse archers with my cavalry, then try to smash in from behind in the engaged cathapracts. but they dont seem to bother in the least.
Eventually the enemy comes with even more units that smash into my already recuced troops, making them rout.
I'm playing hard battle difficulty.
How to win this battle?
and besides.. how come most battles you can only play on the historically losing side?