I don't have any power over Battle Stadium matters nor should I. But I will give you my opinion on that - keep it in social groups. You do not and never will need the battle stadium to do clan wars (not like those actually are ever finished) and tryouts. Just make discussions for each one in the social group, and if you people care as much about clans as you act like you do, you'll be willing to make that concession.
But seriously, it's time you accept that clans aren't coming back. You're better off using your time getting them to work in social groups than fighting for a lost cause.