Well if they’re about to fight Dorry and Broggy then it’ll most likely be a similar difficulty for both of them
That's where you're wrong.
If , a very big if , i don't speculate anymore.
But even if you were to give me a Situational battle between zoro and Sanji vs Dorry and Broggy.
Sanji ifrit Jambe , Zoro King of hell.
Sanji would have to put in more Effort , he ain't one shotting a giant on steroids who probably have better Durablity and endurance than Queen.
Vs Zoro King of hell , one strike should be enough. Assuming he even uses. Zoro havn't used it since wano.
If zoro restrict himself. Yes Same difficulty probably. But again Zoro with ryou is strong as well. His AP is off charts for these people.