Different Initiative attacks for the same model

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?

The Knight's horse does indeed take the stunned model OoA. It is a seperate being despite being ridden.

The second half of your question has been discussed at length recently:

https://boringmordheimforum.forumieren.com/t6632-sisters-of-sigmar-steel-whips

For your first question it is just like a warrior and a war dog owned by the warrior each attacking the same enemy. The knight and horse move as one unit but are still separate as mentioned by VK.

Thanks for the answers! So, does a knight get any XP for a horse's kills?

If not, then I'm thinking the best tactic is to always strike first with the horse, and then have the knight finish the foes off.

You have to resolve close combat in order of Initiative so the I4 knight would strike before the I3 horse. I would say that the knight does not get XP.

Quote :

The knight is I4, the horse is I3. The knight strikes first and stuns his opponent.

You knew that in the first post...

The warhorse is a seperate entity capable of moving, being attacked and attacking on its own if its rider is stunned or dismounts. The knight gains no exp from wounds caused by the horse.

Thanks for everyone's help. It's good to have this sorted out now before an issue arises.