Skeletor's forces need at minimum (vintage) Two Bad, Blast-Attak, Saurod, Blade, Twistoid and Goat Man. Karg, Pig Boy, Dragoon or Draego-Man and more troop builders would be gravy.
I have mixed feelings about Strongarm and Batros because they'd be CC and I'm not sure they should be taller than everyone else (Icer should, but I can just buy his Classics figure instead of a toon accurate one that wouldn't look as cool).