Think of a multi-player-game where you have Team A (2 players) and... nothing more, no enemies:

Really! No joke, no photoshop! Here's the link:
https://www.warlight.net/MultiPlayer?GameID=10721646Host made this game with him and ~39 open seats, settings are
"at start, randomly divide into teams of 5 players".
But he started after i joined, so we have one team fighting no one...
Well, how can you win a game when you have nothing to defeat? ^^