Fair points till the end.
A decade ago the champs were, off the top of my head, Cain, Machida, Anderson, GSP, Penn, and Aldo. There were just as many collegiate athletes in MMA then as there are now, primarily from wrestling but also football and basketball just like today. Are you saying that every one of those champs were not A level athletes? If so, why?
The fact that Rich Franklin was as successful as he was in MMA while being an ex-math teacher does not speak volumes about the lack of athleticism in MMA back in the day; it speaks to the tremendous natural talent he had for fighting. For the record, it's always been that way when it comes to fighting, especially at the heavier weights. Ron Lyle took up boxing in prison when he was 25 and went on to tremendous success in the golden age of boxing. Shavers took it up in his early 20's, Foreman when he was 18 at a work camp, hell, even Deontay didn't get involved in boxing till he was 19. Outside athletic accomplishments are nice, but there are people who are just born to do a certain sport. From Larry Bird to Gretzky to Brady, you have guys who just "got it" at their chosen sport, but probably wouldn't have been able to transfer it to others. That's how I see the fight game. There are some guys who just have a ridiculous knack for fighting and have all the intangibles that can't be accounted for in a quantifiable athletic performance test.
Again, I do agree with you that elite athetes in sports like basketball and football, if they took up MMA instead when they were younger, would have a definite leg up on your average Joe, I'm just saying in the end I don't think the game would look much different than it does right now, which is pretty much how it's looked since the dawn of the new millenium.