Games with less than 5 players on a team on start, should not be allowed to start, or you should be able to jump out from the game with no penalty to the team with less players, and a "small win bonus" to the team that didn't suffer loss of players.

Nobody wants to play a game with only two teammates on their side, and just loose because they failed to join. That's just an shitty experience. One which I just personally tried 4 times in a row.