Sanji’s Powers that connect with Luffy and Zoro

B) Sanji isn’t a leader

C) Important times when Conqueror’s Haki was displayed, both Zoro and Sanji were at them
C.1) Back when Rayleigh showed it (Usopp was at this one too, who knows maybe a foreshadow)

C.2) At Fishman Island, the interesting part here is that Jinbe and Robin treat it like something big while Zoro and Sanji are quite casual about it.

D) Sanji has a weak will or holds no ambition