I've read through and it sounds like OP wants an after the fact ranking system of stats or some sort to give things more playability I guess, I don't really see the point tbh. You say no parsers but your asking for a crappy version of a parse and I guess if this system would bring us closer to an in game parser I'm all for it but honestly I'd just rather have a full parser. As a PS4 user it just blows not knowing if I'm doing awesome or I'm being carried and more often than not my mind makes me feel the later and it plain sucks. Being able to see what my damage is like and others being able to look up in game where my faults in my game play are to help me improve is more important to me than a leader board that won't help me improve. If a leader board system happened as a result of them adding in a parse I'm 100% in, but as of now I value an in game parser over what your asking for.
