I don't understand why two swords style Zoro will be weaker than 3 sword style. It's not like more swords are granting more power to him. He has powerful techniques with 1,2 and 3 swords. It's true, his signature style is santoryou and maybe he is more accustomed to that but his overall feats don't change according to the swords, neither does his use of haki. Imo Zoro is overall stronger than Sanji. It won't be an easy fight, but the winner won't change according to swords number.
Yes Sanji has the speed advantage, if you're talking about the flashy animation against Ain, Sanji showed exactly the same vs Binz. However instead of your subjective argumentation I like to base mine on manga facts, where Usopp stated that Sanji moves faster then a fishman under water. And I haven't seen Zoro do a soru yet. If you're going to imply that Zoro has stronger leg muscles then deserve a ban from this section.