I agree with scaling it way back to a half-dozen characters. So He-Man and Skeletor for sure, then you want something attractive so definitely Evil Lyn or Teela. Both would be better. That leaves a couple spots left for your favorite characters.
For leg sleeves, I personally would ditch the battle scene idea though. My thought would be to have Grayskull and a hero gallery on one leg and Snake Mountain w/ its Villains on the other.