-You could make cav more skill based by, actually making horses respond to pain.
I'm all for a cav getting a kill on me, if they actually get the drop on me. Front or back. But it really does irk me when I shoot a horse straight on as it closes, and the thing keeps charging like it wasn't a member of a species notoriously prone to: 1) getting spooked. 2) suffering potentially severe injuries when colliding with things at top speeds. Of course that would be less so for armored horses.
-That, or maybe a riding-level-based chance of getting knocked off the horse if it gets hit hard (would of course have to define hard). Whether or not the horse dies.
Those are my suggestions.
-Oh and, make lances auto-break after 2 couchkills.