As a khem team three mummies and an extra skeleton to foul/replace with is more than enough to take down most beginning teams, especially with a 4 rerolls which become quite costly in the late game. If one of your players is injured is missing after the first game you already have a backup skeleton to replace him, and as long as you play teams with a decent FF you should be able to get that 4th mummy after your 2nd game.