Yeah, that would be kinda cool actually... It could be a new type of PvP that could be installed into our houses as well (or that little compartment that's inside our ships ). And since our pirates are stronger than our companions, usually, having at least 2 or 3 fight you would be interesting. I'm all for it!
Maybe, if needed- I don't see them reprogramming our houses just to add a Player vs. Companion (PvC?) arena- they could make it like a house game you'd buy in the crown shop, like we would in Wizards! PvC! Where you, and the companions you've selected, fight to see who comes out, victorious!