Good idea, though then you can have a poleaxe, shield, lance combi on horseback again. But i like it. +1!
The poleaxes should be unsheathable.
Suddenly they can have both lance, large shields and sword. No, no no.
The way to solve the large shields issue is to make them unusable from horseback, not to mess with the number of slots they take. If they should be able to be used on horses they I do not see the problem. Lance+cav shield+1H is a perfectly reasonable setup isn't it? I am one of the largest horse eaters... I mean haters.
