Luffy's first loss against Drunk Kaido, was overblown, because being Drunk is actually a boost, and because Luffy didn't know Kaido's abilities and was in a bad mental state.
That isn't really much different between base Luffy getting BTFO'd by Lucci no diff, to fighting him somewhat on par in base before dominating him in g2, or many such cases.
Mashima just makes up new shit as he goes along with no worldbuilding.