I have two new clan features in mind:
1. I suggest clan "stars"/ arrows or other symbols next to the clan name/ logo to show e.g. clan strength (based on average clan rating) and net points gained the last 3 months (up arrow: net point gain, down arrow: net point loss).
2. I suggest clan ladders with rules similar to single player ladders: Players from each participating clan must challenge/ defend when needed (I suggest 5 player challenges). Advantages: Highly competitive/ clans would have to work hard to stay on top, and there would be no need for league seasons or set teams.