You could maybe paralyze the matchmaking process by making buckets in which players of all the elos are ranked. Nobody in the top 100 will be paired with someon

You could maybe paralyze the matchmaking process by making buckets in which players of all the elos are ranked. Nobody in the top 100 will be paired with someone who is in the last 2000 anyways. So why not split it up on every 1000th player and treat them separately. The leaderboard then only needs to modified (read can be done without race conditions) by the top 100 or whatever.