I'd say only have it enabled during warm up mode, and make it fiddle with the teams until all clan mates are on the same side, and it's balanced. Or in pubs have it so the team numbers are the same, and people in the same clan are on the same team. It would help at the end of matches (in pubs) to just keep it consistent and not start with 6v2 because 'oh I wanna be with my clan'.