This is such a misconception Zoro fans create lmao
They think if Zoro kills a random fodder with an special name and Sanji doesn't (despite fighting or having a scuffle with the main antagonist or of an arc and such) then it means "Sanji doesn't fight, Zoro and Luffy do cuz they equal and stuff you know..."
Zoro fans are best friends with forced parallels that end up meaning shit.
I would go further and say that sometimes Zoro has more fighting panels than Luffy. That must mean something big, right... Zoro might be the main character and we didn't knew it, he really might beat Kizaru while Luffy watches and cries because he isn't strong enough, trust me bro, meanwhile Sanji will be getting negged be S-Shark or simply not fighting at all
I wonder why they never mention Thriller Bark tho, where Sanji fought and beat Absalom in a 1vs1, while having to protect Nami and getting stabbed. The same Absalom who gave origin to Shyriu's DF in the post-ts
Zoro fought that bum dead body with Brook's shadow and got a free black blade