Board Thread:General Discussion/@comment-25266931-20161223190810/@comment-26397825-20161227054813

In a livestream they actually said that non-mammalian faunus are rarer than mammalian faunus. So not only do you have to hope your child is a snake, or scorpion, or whatever, but then you have to hope they have an offensive faunus trait. When you look at the odds, Tyrian may very well be a 1/100,000 faunus to be both non-mammalian and have an offensive trait.

Add in that faunus have less numbers than humanity, and no matter how strong a person is they will still get overwhelmed by numbers (which is why Tyrian ran when faced with RNJR, despite having defeated Qrow - his aura was low and he'd lost a valuable part of his fighting style), and it becomes a bit more obvious as to why faunus don't just decide to rule the world.