This is something I didn't think too much about. I still think that rearing should be in the game as it gives a lot of tactical depth, but definitely the Ctrl-J combination must be improved. And perhaps a longer cool-down time to make it less spammed? It'll be interesting to hear other's thoughts on this.
All feedback is welcome
If stamina is introduced it has to be with a lot of testing to ensure it doesn't take away a lovable simplistic nature, but rather only adding some depth as you said.
Whilst I certainly don't want heavy cav to be 'immobile turrets', they should have some maneuverable consequence due to their armour, so moving their sword side-to-side more slowly for example. It'll be definitely important, as you say, to ensure that there is balance between hussars and heavies so hussars can be faster and not run laps around heavies and that heavies can be tankier but not as maneuverable or as fast as hussars. I'm not saying they are totally unbalanced in NW, just this balance needs to be thought about when creating the dynamic combat system for cavalry in Holdfast. Good suggestion.