I never lost in my adult life, and I wrestled in nearly every bar in that state that I ever went into, and in many other states... plus probably a hundred guys in the Army, etc.
Then one night, in my 30s, I met a guy in Davis, CA, who beat me. Couldn't believe it. So we wrestled again a few times and he never beat me again. Doesn't mean I beat him everytime afterwards, either; we had a number of draw matches. Anyhoo, we became friends and he suggested I go with him to the next big event. So I did, and lost, BIG! To a guy half my size.
There are some really strong guys in those things. But I never saw anybody with an outsized arm, lol. And I'm having a little trouble believing it, actually.
In any athletic competition I've ever seen, you have to have a well-rounded physique; e.g., the fastest runner in the world didn't just have big muscular legs and nothing else going for him, etc.