give concrete elements what you say has no meaning or objectivity
zoro with his most powerful attack induced with CoC did almost nothing to kaido
sanji with his most powerful attack will do even less damage to him
I can almost guarantee you a Zoro Ashura now would be on another level than the one that scarred Kaido
Oda has always drawn black lightning coming from the user's weapon/body when conveying usage of conqueror's coating
This was not present at all in the panel with Ashura, which leads me to believe that if ashura was in fact ACoC there was very little of it involved (also, I wouldn't say giving Kaido a permanent scar is almost nothing but alright)
Now, Zoro is imbuing all 3 of his swords with conqueror's haki and clear black lightning emitting separately from each one. Kaido describes people who can do this as a "few of the very strongest"
You're saying Luffy would 1 v 9 his entire crew but he would have high difficulty in just a 1v1 against Zoro
As for Sanji I have no answer because I don't know if Ifrit Jambe can actually harm Kaido