. Its obvious Mars is a CoC Haki user as well, so is Saturn. Bonney also wasn't able to change Saturn's age by using her DF hax, similar to what Kaido, BM countering Law's teleportation.
CoC user Luffy didn't understand Kaido was using Ad.CoC on the rooftop for a while, he figured out later as if it was a big secret.
Luffy was simply thinking Kaido was using a giant amount of CoA, otherwise if there was clear differences between Ad.CoA and Ad.CoC, he would immediately know it as Luffy himself is CoC Haki user, but he didn't, he needed time.
Law replicated Emperors advance Haki by overextended himself when he reversed Doc Q's DF Hax, and produced the same exact color of Ad.CoC of Shanks's or Rayleigh's. The difference was Law needed to struggle and overextend while others does that casually, as we see Kaido, BM vs Law's teleportation, Teach creates giant lightnings with ease, and Saturn's casual defense vs Bonney's DF hax.
Scabbards combined CoA produced a lower level of Oden's Ad.CoC on Kaido.
Zolo needed more CoA to use Enma, and thats when Zolo used Ad.CoC to boost his CoA, its not a coincidence.