Out of that 20 people at least 60% of them are in other high-tier spar guilds as well. Half of them are literally just the same roster under a different guild name.
I would also as of now only consider 3-4 guilds to be above average and good enough to compete, any hosted tournaments would be a majority of noob guilds who think they are good, same with the players in them it would tend to be the same players winning and anyone who joins just to spar for the tournaments is going to have a terrible time becoming good at it.