Once again Zoro is never, never, not once, stronger than Luffy at any point in the story. Never. It can be chapter 1000 or chapter 1 or 256 Luffy was/is stronger than Zoro.
Luffy at chapter 1000 > Zoro chapter 1000.
Chapter 1000 Luffy is stronger than the one against Kata. How much stronger ? We don’t really know. He has a good haki upgrade in attack power. But Kata was still superior to WCI Luffy. Under normal circumstances Kata would have beaten Luffy. Fair and square. Kata acknowledged Luffy at a legitimate opponent. It doesn’t mean he was stronger than him.
Kata > Post WCI Luffy / beginning of Wano.
I think Luffy pre rooftop adventures and training made him overall as strong as Kata. Maybe extreme diffing him for real this tim
So Kata / Rooftop Luffy (before adCOC) > Rooftop Zoro
And King > Zoro currently.
Zoro needs to find the key to beat King once he will find that he will be able to fight him and overpowering him.
End of Wano Zoro > King : apex high tier / lowest top tier.
End of Wano Zoro >= Rooftop Luffy >= Kata / King > Rooftop Zoro
That doesn’t change the fact that he is a bird and could have an hybrid.
Kaido has a mythical Zoan and has a classic hybrid form.
For now from what we know King was in hybrid. Against Zoro he used normal form, sword, full Zoan, weak long range fire attacks, and partial transformation that terribly looks like hybrid.
King maybe has awakening and we barely saw his lunarians powers. So he still has rooms to impress more.
I say that there is 70/80% chance that what we saw barely was King hybrid.