Say someone has introduced a friend in but they have very high level characters so are in a high level game why not make a game mode that limits characters level to say 2 so people don't get destroyed by level 5 and 8.
What I purpose is mode that states you cannot play a set character if they are above a level but if someone else has a lower level that they can play. This will help others learn different tactics and help newcomers and old ones level up others.
Thank you for your time