Dwight Muhammad Qawi who had a similar style to Joe Frazier, actually didn't do that bad vs George Foreman. And a shot Joe Frazier in the rematch vs George Foreman done ok for 4 rounds aswell.

I think a prime Joe Frazier does better and maybe has some moments, but i think he gets stopped in the 8th round or so. If Dwight Muhammad Qawi can last 7 rounds while not disgracing himself i think a prime Joe Frazier could last a bit longer.

But again George Foreman's weakness wasn't brawler's it was boxers like Peralta, Ali, Young, ETC.