Fortnite has a communal game for groups who like contributing to a less ego bruising group effort and a KOTH game for ego bruisers. Capture the sheep is a communal game once you start jailing players planes with the He111 over watch or a jeep at the sheep pen. Or have the GV's been disabled along with bombers these days. Sheep stealing is a very cooperative game unless you like being jailed while two or three guys steal all your sheep unopposed. It does not work very well as a 1v1 dueling game either since it only takes one random ping to jail you and you need a countryman shooting you to free you. Everyone gets randomly pinged no matter how good they are in steal the sheep. One side wins but, it's not an ego bruiser like KOTH type of games since no one gets shot down from fights in steal the sheep. You cooperatively steal sheep to win.
Have you honestly ever played fortnite before? How is fortnite a game that’s classified as cooperative? It’s a battle royal, fight to the finish, last man standing wins. Everyone is out to kill each other. There is a Duo and Squad mode (4 player max size). The squad mode is the closest thing to “cooperative” gameplay as you will get and even then it’s not much.
Fortnite has muchhh more ego bruising going on over Aces High. Every fortnite Friday, every scrim match, every big payout tournament there was extreme butt hurt going around. Now the big butt hurt is from people not getting invites for lack of points made during pop up cup series matches.
Like junky said, KOTH was the closest thing you can compare AH and Fortnite together.