Please, let me assume there are tons of MKs, one of the main arguments of proban is that MK is overcentralizing. I can tell you that there is probably at least a 1 to 5 ratio between number of MKs and snake.
Now, your argument falls appart when we take into account the bell curve. Il give you this distribution.
Please follow my reasonning:
Pretend there are 10 snake users vs 50 MK users. Out of these, 40% of them will fall approximately at the mean. 20% will fall just below the mean, and 20% just above. Finally you get a 10 % that will be REALLY good and another 10% that will be really bad.
This gives
1 really good snake, 2 good snakes, 4 average snakes and 2 bad snakes and 1 awefull one.
For MK, its 5 really good, 10 good, 20 average, 10 bad, 5 very bad.
Your method catters to taking stats only about the best top 3, that means:
3 really good MK
1 really good snake, 2 good snakes.
Method favors MK, not due to how good he is, but due to how popular he is. Now even with this, MK has a higher mean skill level due to the amount of pros that switched to him(and not to snake, pros switching to a better chars usually switch to the best, which is perfectly normal). DESPITE ALL OF THIS, MK and snake top 3 results are very close, MK didnt win a national in 8 months and doesn't even have any MK that gets close to ADHD, Ally or M2K in terms of wins/consistency. Maybe MK ain't as good as you make him out to be.