I caught your stupidity, all those people you listed there, luffy foght post timeskip. Ya, before he had haki. He was also the first warlord to beat up 2 warlords f*cking post time skip.
When on earth did LUFFY fight Aokiji post time skip, or Smoker or ONE warlord, let alone two? Luffy has only encountered a Pacifista of Kuma (not the actual Kuma, who is a LOT stronger than a pacifista), Boa Hancock (who he did not fight) and Jinbei (who he had a one-second ruffle with that was nowhere near serious). He has not encountered any other warlords, so I dunno where you're getting the idea that he fought two warlords from.

Law fought Smoker. Doflamingo fought Aokiji, and even then it wasn't a proper fight. You haven't caught any stupidity...
And even if you were right that Luffy had fought them post time skip, that doesn't eliminate the validity and significant consequence of the facts stated before... Luffy wouldn't have survived his encounters with Aokiji, Smoker and Kuma if not for his relation to Garp and Dragon, which saved him via Aokiji not capturing Luffy due to a favour for Garp, Dragon saving Luffy from Smoker at Loguetown, Kuma not capturing Luffy and the straw hats because he was secretly working for Dragon.
On topic: I feel like everybody is ignoring the original post. It's talking about true individual potential of a character rather than a character's capacity to become the best, which can be achieved by all manner of means; teamwork, allies, blah-blah. I get where the OP is coming from with Law having individually reached where he has over the two years, suggesting that as an individual, with the use of his skills, he has greater potential... factually I guess. But the thing is, Luffy has hax that ignores any facts: character hax, plot hax, luck hax, friendship hax. He has the ability to unintentionally and randomly possess the right and perfect choice of route, friends, connections, powers, personality and feelings for him to become King of the Pirates. Oh, and this hax would probably allow him to defeat Law regardless of the tactics Law would pull in battle.