I have done some testing with the rock wheel and dark wheel being used as defense types. What I've found is that rock gets ko'd a lot easier than dark against a storm attacker. The dark wheel was the hasbro version
Combos Used:
Attack: Storm Pegasis 100RF
Defense: MF Rock Bull C145WB, MF Dark Bull C145WB
Combos Used:
Attack: Storm Pegasis 100RF
Defense: MF Rock Bull C145WB, MF Dark Bull C145WB