I don't think so. Sanji is not someone who is at his best in the air. Just because he can fly with Rokushiki, doesn't mean they make the great battle, the only thing which is shown out of his aerial ability is mostly escaping/rescuing, and obviously, he will be inferior with his floating ability to someone who can naturally fly. A better air battle is with someone like Marco, where he and king both have natural flight and not some trick to stay afloat(can take Jinbe and water as example too). King being a swordsman can probably use his swords skill too while afloat.
Next point just because king can fly doesn't mean his opponents have to do so. Take kaido himself, he can fly but we can already see he is in his normal form to fight scabbard since he can use his kanabo skills. I would assume King too most probably won't be using his flight form but more of his sword if possible.