Yes it is fair. As one of those people, I can tell you that it is a struggle to keep the top rankings. =)

They actually gave an even less percent chance before. The 15% it is now is pretty fair.

If I could move this thread to Game Suggestions I would #WishIWasAMod

Anyway, a possible way to counteract this "unfairness" you speak of is to slow down or even stop the clan extensions. I think 25 members in a clan would be perfect.

This way new top players who are pretty good can seep into the 4th, 5th, and 6th place clans. This gives a higher likelyhood of changing the positioning of the top 3 clans, dispersing the new mythicals to more people.