I don't think you quite understand what I'm trying to say.
Light footman = fast, low upkeep
Heavy footman = slow, high upkeep
Light horseman = fast, low upkeep
Heavy horseman = fast, high upkeep
There is our inconsistency and so the light horseman is at a disadvantage. I could be the richest player in cRPG, but if myself (as a light horseman) fought another player of equal skill (as a heavy horseman), I would always lose.
even if you run around naked with 8 athletics you will never catch anyone riding on horse [donkey is exception, and not really a horse]. lemme fix this.
light infantry: decent speed, low upkeep
heavy infantry: slow, high upkeep
light horseman: extremely fast, low to medium upkeep
heavy horseman: good speed, high upkeep
note: by heavy horseman i mean a guy who has armored horse, not just a guy who rides a horse in heavy armor.
you gotta understand that unarmored horse trades off armor and hitpoints for speed,upkeep and, in some cases, maneuverablility.