I have a suggestion which I think will help with user rank structuring etc..
My suggestion is to add User Ranks, just like user titles but you can only be appointed. There's no certain amount of points you have to get, you must be appointed by an administrator.
Let's say, Jim Bob is in the group "Registered". And you want to make him the leader of the chess club, You create the User rank. Then you can appoint the user as "Chess Leader" but that user is still in his primary group "Registered". And you can add an image or an icon for each rank