I think the most difficult part stems from the fact that the ranks don’t degrade.
Therefore a Diamond player can keep that Diamond and there’s no chance of you coming up agaisnt them and “taking it away” from them, if they don’t play.
I know in the past, people would hit Diamond on their main, makes new account and very quickly hit Diamond again.
It’s the same person, now taking up 2 Diamond slots and fooling the system into thinking that there are two top players instead of 1 for that particular Skill Set.
And I’ve known Diamond players make 2, 3, 4+ accounts.
This is more of a Microsoft issue as they have made having secondary accounts so easy.
These accounts should be limited and unless they have full Xbox Live Gold (excluding trials l) - they shouldn’t be able to play Ranked Games.