Manga suggests you NEED ACoC for King? So Rooftop Luffy would lose to King? Law and Kid would lose to King?
Your King wank has reached new levels of stupid.
I don't think you specifically need ACoC to deal with King.
You need either genuine top tier AP or a way to properly bypass his flame-on defense.
As far as pre-ACoC Luffy goes, I don't see how he would be able to damage flame-on King. It seemed like his internal destruction proficiency was either not good enough to properly damage Kaido...whether or not it would work on King is debatable
I stand by what I've said about King before:
He is fodder for top tiers to deal with, but nearly impossible for high tiers