Boxing is definitely a contest of matchups oftentimes.
But there's no way Tyson --in shape, & not dinking through the fight-- would've been beaten by Buster. If he'd taken him seriously like he always did someone like Razor Ruddock — then Buster woulda gone down a lot quicker than did Ruddock (who was a very good fighter who woulda been champ at least once in most eras).