Groups are not synced with the game, that means when you create an mission with already predefined groups, in group management everyone will be listed outside the group and that is really big problem.
Another problem is when someone switch group different way then group management, for example script commands. Guess what, in group management it's not synced and player is still in wrong group.
Group Management should mirror the actual group state which is in the game, it shouldn't be separate !!!