I'm still playing a vanilla 1.3 RTW campaign. I started as the Scipii, but recently started a Carthage campaign. I guess it doesn't matter who it is, though. It seems whenever I charge a unit, the leading member of the cavalry unit will fly off his horse and the horse tumble to the ground when they hit the enemy. I've lost more cavalry members that way. I use the cavalry to flank the enemy most times, unless it is some light unit like archers. The enemy will be facing away when my cavalry attacks, but the cavalry still fly off their horses.