ACoC is not "advanced" CoC. This term came out of the fact that Luffy learned ACoA before using it, so they assumed ACoC is like ACoA. It's not. ACoC is simply using the basic Haki flow that Kiku and Kinemon are using, and combining it with CoC.
ACoC would be advanced if it required ACoA/internal destruction Haki. It doesn't.
Just because
Luffy learned the actually ADVANCED cuff destruction CoA Haki, it doesn't mean you need it for "ACoC". Yamato had "ACoC" without ACoA.
These are just different applications of Haki. CoC can be used as Haki blasts, coating, observation killing, etc.
What Gaban said is you need to
consciously use it for it to be useful and help Luffy. Zoro has NOT consciously knocked out fodders. He knocked them out as a result of Haki pouring out of Enma. Not that he can't learn it, but Gaban made it clear that he still has no idea what's happening.