That's barely the premise. You aren't getting it at all.
The main argument is pure dialogue:
- Zoro before Luffy fell "Leave Kaido to Luffy", which Sanji acknowledged.
- Momo after Luffy fell "Luffy will win". Neither Zoro nor Sanji's reactions were shown here because they already believe he can win, as shown before
- Yamato after Luffy fell "I can't beat you, but I will hold you off until Luffy returns!"
None of these involve Zoro, before and after Luffy lost his Haki. And narratively, it does not matter that Luffy fell. This is the same MC that told his crew he would beat Crocodile, only to lose, then make the proclamation again with Water, only to lose AGAIN and fight with his blood.
Your arguments make no sense, they are based on fan wishes and "how can something be X" without actually realizing that your opinions dont matter to how a story will go.
Zoro vs King is shit writing? Too bad you aren't the author. Zoro using Enma on Kaido is set up? Yea, it already happened between 1000-1010, the plotline is now over. He cut Kaido. He couldn't kill him. He's leaving it to Luffy to win. We got from points A -> B -> C already with this plotline. It finished.
Not to even mention that Marco's fight with King has yet to be shown at all, King has yet to use his hybrid, unlike how Queen has for Sanji (same can be said for Jack), and Zoro himself was the one interested in helping the performance floor.
There you go, nothing to do with Zoro and Sanji facing the number 2 and 3 respectively, but very clearly also part of the argument because it almost always happens.