Getting old with the GP disparity - every level is having this problem besides Kyber 1

I don't see why this is so challenging an issue. Start with the current matchmaking, then after you've got everyone grouped further refine the matches based on number of gls bare minimum. A gl will trump skill with a given roster when you don't have enough tools. Then you get people who are at least close on number of gls, and there's a reasonable chance of victory for both sides