I'll give you an example of how this doesn't work.

Overwatch.

It simply does not work no matter how you cut it. You can be a gold level mercy, but then when someone else takes mercy (healer) (Or perhaps you just want to DPS this day) and pushes you to say, a solider 76 (dps) and youre just a bronze level player as 76 it doesnt stay true to the overall ranking you received.

While I get your idea, and how it COULD work, the fact is, it can't.