The actual ZKK theory doesn't dispute Luffy winning against Kaido
- Sanji being a wing has nothing to do with him having CoC, otherwise you're just using the "Zoro can do it, so Sanji can do it too" argument
- If Sanji has qualities of being a CoC user, they are nowhere near as apparent in him as they are in Zoro & Luffy, who had strong hints of getting it way before they actually did
Regardless of whether or not you see Sanji as a potential CoC user, we've only ever seen ACoC as a black lightning trail coming directly off the person's body or weapon. It's silly to think that a random
white lightning streak has anything to do with it when those kinds of visual effects have been in the manga for years
Not to mention the fact that Sanji or Kid just casually using ACoC when Oda went out of his way to make it a huge deal for Luffy & Zoro unlocking it...would just make no sense