A knight is on horseback. The knight is I4, the horse is I3. The knight strikes first and stuns his opponent. Now the horse attacks. Does the horse need to roll to hit/wound/injure, or is the model automatically taken OOA?
Likewise, let's say that a mutant has an extra arm. He is armed with a sword and a great weapon. He attacks first with the sword and stuns with it. Does he need to roll for the great weapon?