^ This was Oda showing that Luffy needed a firepower buff against Kaidou. And hence he was given CoC coating.
^ This was Oda showing that Sanji needed a firepower buff against Queen. And hence, IJ came into the picture.
You'll never find such a statement from Zoro about King. But instead,
CoC coating had nothing to do in Zoro vs King, it was more-so to tame Enma.