Yes, a pro boxer is going to lose a wrestling match w a pro wrestler. Or a judo match against a judo master. The CM vs FM fight would be a pure boxing match, right?
Couture would not have done too well against JT, (or any other boxer), using boxing rules.
UFC started out great as a contest between different martial arts w the Gracies offering to fight anyone for big $$ and never losing(?) They were demonstrating that Gracie JJ was superior to all other martial arts. The fights were awesome as hitters tried to get in a quick knockout or at least disabling punch or kick before going down and never succeeding. They are true masters of their craft. The fights were exciting for a while because you really didn't know if someone might beat them. Eventually it became clear that no one would.
There are no more Gracies or anything close in MMA. Generally speaking, all of the fighters use the exact same skill set and style and all are sort of fighting ombudsmen, trained in grappling and boxing or kick boxing to a certain level. Almost all of the fights are like bar fights or street fights that start out trading punches until someone goes down and then it's a ground fight. Never w great grappling or punching though, in fact the boxing part is always pathetic. I've seriously seen better on the street.
Are they athletes trained in a sport? Yes but I'd rather watch paint dry than their "sport". I just tried to watch a compilation of "greatest KOs" of MMA on YT, it was mostly guys getting kicked in the head and then the kicker dives on the unconscious dude and starts pummeling his head until the ref pulls him off. Absolute fking garbage. People never even did that in the alley behind the bar where I'm from. The punches are thrown from bums. No one has any defense whatsoever from the flying foot or fist.
I realize that boxing isn't what it used to be w the likes of Mayweather in the game but I'm old enough to have seen the greatest of all time in their prime and plenty of just amazing fighters. This is a sport:
https://m.youtube.com/watch?v=3PPhyBUsxaA
Imagine CM trying to throw hands w one of these guys. Yeah.