I see that the enemy has some treb archers, I don't want them to be a frustration so I bring some Armenian Heavy Cav along to help out. For some frea reason the Treb archers start apart from their main army on a small hill. I think "awesome! attack!" and charge my Horse up the hill.

I got slaughtered. I killed one archer.

How is that in any way possible?

PS - I used the wedge formation and they were 3 deep. I totally bowed their formation but it didn't break. Valour?