Cheat herding

So, I work in AI and machine learning.

I understand the massive, massive complexities of detecting cheats, tracking the users, etc.

Here's what I don't get ... the absurd KD ratios in games, why not exploit that by ... not flagging as cheats (although you could do that, try to figure out how they're doing it) ... but by herding those players into the same lobbies.  Let them shoot each other up thru walls, etc. ? (Sort of like ranked play, but based on running averages of KD, etc.)