Let's be honest, sanji fans didn't give a fuck about CoC until Zoro unlocked it. All of a sudden he's "always been foreshadowed" to get It.
Sanji fans just want a blone Zoro, it's comical.
I hate CoC, it is the worst power ever designed by CLoda. If Zoro didn't have it, he would have never become WSS. It makes any training useless if you want to reach the top. And you can't do anything to unlock it.
I'd have preferred Zoro, Kidd, Yamato(and Sanji) with no CoC. Now that Zoro showed it, Sanji has to possess it too. It is not just a matter of strength, their rivalry, the dynamic in the crew, them being wings of the PK, nothing we read until now would make sense otherwise. Zoro and Luffy are not a VC-captain duo with 7 other random crewmates like the Kidd pirates or Shanks crew.
Not to mention the fact that Yamato, and ACoC user, will obviously join the crew and put Sanji in an even more secondary role.