Having groups depending on the sort and number earnt over the last few weeks might work. Of course, then the competition for being hardcore is, facing better opponents, but then even if it results in mini leagues there’s little glory in being best in the 3rd division, even over last in the top one.

Perhaps klan versus individual domination would work. Then when you win it *is* your skill and not 95% the work of your friends, while on a klan level, it’s a shared victory.