While they obviously both happened during the same time they both required their own thing separate from the other.
When it comes zoro struggling with enma the main reason was because the blade was testing him. Enma was pushing zoro to his limits by forcing out as much haki as possible. It was only till zoro fully excepted the challenge and not only that but emposed his will on it. He took its moniker along with unlocking conquerors in the process.
A lot of the confusion is while they’re separate revelations they both became fully realized pretty much at the same time. Him passing enma’s test and unlocking conquerors in the process + him figuring out how kings lunarian body works are still 2 separate things that aren’t a necessity for the other.
Even in king of hell mode all zoro and king were highlighting was zoro figuring out his body.
- Conquerors was never unlocked to counter and beat king
- It was never necessary to hurt him
- Zoro never needed it to hurt lunarian in general
- It really had nothing to do with him
- People without conquerors can hurt and even beat lunarian