Training helps, of course, but it mostly helps against people who haven't been trained. No sane fight promoter is ever going to put a woman in the ring against a heavyweight male champion, for the same reason that they aren't going to put a heavyweight fighter against a flyweight. Someone is going to get hurt. Probably badly.
It's also important to remember that we're talking in generalizations here...there are very strong women and very weak men. But at the highest levels of competition...everyone is really, really good. And when you place really strong women against really strong men...for the most part, women get blown out of the water. There are a couple of sports (mostly endurance based) where women might honestly be able to go toe to toe with men, but 99.9% of the time they get smoked.
None of this means that women are lesser than men. Female bodies are every bit as amazing as male ones - honestly more so in many respects - they're just designed with different criteria in mind. When you have to carry a self-replication factory around inside of you, it really cramps the design specs.