The actual interesting thing is that
1) Haki is confirmed to be part of Swordsmanship (you don't say)
2) Zoro defeated Flame On King
It was clearly implied that after Zoro got Adv CoC, King started fearing him; that's why he went fighting from distance and trying to use speed to dodge and flank
Also remember that Flame Off King is still one of the most durable characters: he could facetank Rooftop Zoro's Ui Tora Gari with almost zero damage, while a weaker move from same Rooftop Zoro (Tatsumaki) could cut Kaido deeply