all that means is that sanji spent some time bandaging zoro after they exited the rooftop. there is nothing that says that luffy spent "several ten minutes" at the rooftop. and if you're looking into this much detail, i'm sure you understand that the timeline of onigashima isn't linear.
He was talking about luffy's ceiling and compared him to the likes of Roger, Newgate, Rocks, Shanks and Oden (all who are confirmed or most likely adv CoC users). He clearly doesn't compare him to the likes of Big Mom, Garp because 1) they aren't pirates who he respects, 2) they don't resemble luffy, either in character or in ambition or in terms of his ceiling.
You do realize that Zoro very clearly says that he is putting his all into this one final attack to save his captain's skull from getting crushed. And by virtue of Enma drawing out his latent CoC with its properties, he is able to infuse and use it in that desperate Ashura to scar Kaido. When he tells Kaido that he doesn't understand what he's talking about, its very clearly implied that its a one time thing unless Zoro works on it and masters it.
And as we see in Marineford, people were talking about Luffy's potential when he, unconsciously uses CoC. The exact same thing applies to Zoro here as well, when he scars Kaido.
If you think Zoro used basic CoC in Ashura and basic CoC can scar Kaido, then explain how and why the only scar Kaido has is from an attack which is canonically confirmed to have been infused with advanced CoC. Kaido must've met / fought with so many other basic CoC users in his life. Why doesn't he have more scars?
You really think that its just a coincidence that Oden's Togen Totsuka and Zoro's Ashura Farce of the Dead were the only attacks to scar Kaido, ever, but Zoro didn't infuse Conquerors into his attack?
Saying it isn't linear after I have shown proof is changing the goalposts. Sanji took several 10s of minutes to wrap up Zoro and get going, then there was additional time taken for Sanji to reach queen before the message of Luffy's defeat went out.
Garp resembles Luffy greatly, and was an equal to the PK, he just wasn't trying to be a pirate or the pirate king himself.
No, Zoro reached the initial point of displaying CoC, Kaido was shocked Luffy had a CoC user under him, after saying CoC users don't work well together etc. from his Rocks experience.
Yes POTENTIAL, not actually having actualized advanced CoC which is incredibly rare, you don't even need that to benefit from the willpower and passive abilities of base CoC...
Scars are plot related consolation prizes, Oden lost, but he scarred him, for fake hype. Again Zoro was outclassed, as he admitted he couldn't knock Kaido down, but Kaido said he should be happy with the scar. Oda isn't going to trash Zoro as a character without some sort of consolation prize, when he beats King, he probably won't scar him, despite him being less durable, other characters Zoro has beaten who don't have scale defence or regeneration, and got almost bisected by him in the past have walked away with zero scars.
Enma was hyped as the blade to wound Kaido in it's introduction, but it has to be advanced haki that isn't shown in Zoro's attack.