He would have been completely useless with swords, because he isn't focused at raw strength blunt attacks that can push the target away, like Sanji's attacks do specifically, everyone can see how far he sent Queen flying so quickly.
And thats the main reason of why Zoro would hurt Luffy more tho, but in Fuusen mode, wouldn't do much
I think some retards failed to get the idea that Mars was the one who absorbed the vast majority of the attacks, not Luffy.
In this scenario, Zoro would need something like Nunchakus (like the stone pillar he used against Zombie Oars) in order to contribute at sending Mars flying and taking his out of the arc. So if he was there, his impact would be very low compared to what he can do.
But Sanji was there so that was the main reason they achieved their goal anyways