The Isle of Man is an important asset. You need it if you are to unite the Isles together as a super-power of the Gaelic west.
Godfrey is young and of little threat to you. He will soon come around to your way of thinking, and you don't wish to lose any of your men in a pointless battle.
Offer him limited rule with you as overlord. With your experience this is surely a good option for both of you.
Which card will you play?