Why not?
King only tanked Zoro's strongest moves when his flames were up, before Zoro realized that he needed to cut King when his flames were down. With KOH, Zoro never needed to asura. Also he had a timelimit due to the mink medicine.
Imo, based off rooftop portrayal, ACoA Zoro could have probably beat King extreme diff at most had he gone into the fight fresh and enma didn't go out of control.