Yeah, I only got to HA 2, it takes some luck to hit a footman while riding. I found it good enough to dismount cavalry and horse archers, though, as long as you stay reasonably close. This is one of the main things you are going to do, and needs lots of maneuvering, so rising riding above the requirements of your horse makes sense. When you aren't in danger you can slow down to shoot, or backstab people.