That's why they're breaking into Asia specifically China. China has the most people with actual MMA and kickboxers.
Khabib is not the only successful Islam fighter. And not all Islam are the same. There's also race Islam. So the only fans he will be drawing from are Russian Muslims.
Asian countries like China is much more united. Look at Long Yi, Yao Ming or Jeremy Lin. Everyone was watching them. We need a Chinese superstar.
Not to mention Islam is the religion of peace, so they wouldn't watch a violent sport like MMA anyways.