Your headcanon doesn't work here mate. Zoro himself admitted he couldn't draw out any blood from king himself. And for Marco he didn't fight to win the battle. Stalling was his intention from the very beginning. Even he knew it's too much to against both king and Queen in a death match. That being said nothing implied Marco used his strongest attack against king. In fact the Marcos visible best attack was tanked by Queen not king. And that was his claw attack to queen's face and Queen didn't suffer any lasting damage even against it. So either king's defense is over hyped or zoros AP is actually a joke. He couldn't even make Lucci go out of conscious while Luffy did that with a simple punch.
Either way this proves how wrong zorotards has always been
Everyone knows this since ZKK. Anyone with a brain knows never to take zoro fans seriously