I can't see any downsides to this other than a bit of work on wargamings behalf.
As it is at tier 10 it seems most games end within 5 minutes because one team gets stomped to death by a vastly superior team.
My proposal is pretty simple, the same as the matchmaker currently tries to give both teams roughly equal numbers of players in each tank class, it could split players into 5 brackets based on personal score, something like 0-2k, 2-4k and so on untill 10+ and then try and match those 5 as best as possible agaisnt each other, so a team can have 4 players from one bracket, 6 from another and 5 from another.
I think this would hugely help the game, especially at higher tiers because both teams would have roughly equal skill levels so fights wouldn't be a complete stomping. It would make doing well feel more rewarding too, it's nice having a big damage game but when the enemy basically gift it to you it doesn't feel as good as when you work for it.
Thank you for coming to my TED talk, any thoughts?