As far as being a successful fighter, i guess a person would need to make clear as to what arena are we speaking? MMA "sport" is a whole lot different than what happens out in the world, and being "successful" takes on a entirely different meaning when things are for real. I love BJJ, and i love to wrestle, they are both great bases for MMA sports, but for real world scenerios they would not be at the top of my list.
That being said, MMA sport coverage is all over the place, the new generation is growing up with it, which means the bad guys are exposed to it as well. The likelihood of encountering a person on the street that has some MMA skill is not that far fetched, i have experienced this first hand as a bouncer. A few years ago all you used to see in a fight was wild punches, some sloppy grappling / groundfighting etc, now you see guys shooting for takedowns, going for submissions, changeing levels, going for the choke, as well as striking. It's definitely a new game these days, but i can tell you from experience, you need to think outside that MMA box if your going to talk about real fighters.