Let me explain. I’m a max 12, and was a th9 years ago. I no longer have a grasp on what’s available at th9 or any other THs, so when a lower TH player requests to join the clan, I have no way of knowing how far along they are for their TH level and how rushed they may be. It would seem like a statistic/rating could be developed from 0-100 to include in player profiles stating how far along they are in their specific TH development.
honestly I just look at their troops and heroes. If I can see what troops they have maxed, gives me a pretty good idea of what they use for war or farming, and higher level heroes is always a good sign.