They will probably get along for a while. I would let them grow out until fall or early next spring when the hormones really kick in then pick your favorite one as a keeper and re home or butcher the other two whatever you are comfortable doing.
I see 3 cockerels. #1 definitely have red starting to come in on their shoulders and saddle area. #3 I don’t see the shoulder patches yet but I do see copper colored saddle features starting to pop out on his back between his wings.