Mate, it's all comparative power scaling. (Mainly where stuff like "Admiral level" or "Commander level" stems from). Yes, wins can be "unfair" but when Oda establishes a NARRATIVE, you can't fuck with that.
Doflamingo > Law (that was narratively clear)
Law/Kid/Luffy are Top 3 Supernovas, hence Law > Urouge (narratively clear)
Urouge > Snack (Brulee praising his win, and Snack sighing at the Worst Generation)
To argue that these characters can't fight Commanders is simply dumb. Cracker is irrelevant, because Oda never established a NARRATIVE. With Luffy and Katakuri, he did however, and by the end of WCI, Oda considered Luffy > Katakuri.