I think it would be a good idea, that as well as having a required trophy to join a clan you can choose if you want to make a required level to join the clan. This way, if someone is level 100 but only has 500 trophies, they can still join your clan because you set a required level to 80
Just pay attention to who you allow in your clan. Only I and my two co's are allowed to accept requests or send invites. Problem solved. But I admit I do see your point. I just don't see a need for it. A lot in the game is based off trophy count, not much is based off your actual level.