I had thought I put this in the OP, seems I didn't.
The rat king told him he would be indebted to him and that their friendship would pay off. He took this to mean that he could tell the cat to leave, and then ask the rat king to have his rats stop hunting the villagers, since the rat king apparently (I didn't really read their convo) told him he hated the orcs.
I agree with you personally though
