What if having more options is actually a good thing? Maybe those 47 styles exist because different parts of the app really do need different looking buttons. Trying to force everything into one or two styles could make the user experience worse. The real problem might not be the number of styles, but just poor documentation for the devs on when to use each one. Fixing that guide could be faster than rebuilding the whole system.

Just pick one and start using it, you can always switch later.