Zoro has the AP advantage with Buso which doesn't really tax his stamina much at all to compared to base, and even then his durability even without buso will allow him to defend against Sanji's attacks without much issue; he also has the benefit of having swords to defend with compared to Sanji who has to use his own body which will allow Zoro to avoid damage far better. And assuming Zoro's Buso AP isn't enough (Keeping in mind it will also grow stronger throughout the fight like it did in the King fight) he can further amp it heavily either by unleashing Enma or using Haoshoku or combing them, or using Asura etc.
Sanji's durability with his exo-skeleton or buso sort of get negated here for two different reasons. Zoro's buso potency scales above Sanji's and thus the defenses (even against sharp objects) that buso would grant Sanji would be nullified due to Zoro's buso. Sanji's exo-skeleton's resistance to blunt force and blades works similarly to Daz Bones (Minus the regen) meaning assuming Zoro's AP wouldn't be enough if he utilized Goken it would allow him to cleanly cut through Sanji. The Exo-skeleton's regen that actually heals wounds like cuts etc is too slow acting to be relevant in the fight but I guess if Zoro cuts through Sanji's bones he should be able to repair them.
Zoro's own heat resistance & Buso's heat resistance should be enough to completely resist Sanji's Diable Jambe flames and although it wouldn't resist Ifrit Jambe completely he should still be able to mitigate it's heat some what due to Buso as Sanji's own buso was partly responsible for allowing him to resist Ifrit's heat. Zoro also has the option of using Fox fire style to turn off Sanji's Diable or Ifrit Jambe temporarily if necessary.
Base Zoro and Diable Jambe Sanji should be comparable in speed based on their scaling chains, with Sanji's enhanced speed or Ifrit Jambe being far faster. Sanji's reaction speed would scale to his enhanced speed and Ifrit Jambe and Zoro's own reaction speed would scale around that level via reacting to King w/ his flame off, Zoro could combat being slower by using his skill similarly to what he did against Flame-Off King, his lai attacks would also blitz Sanji although Sanji's skill and prior knowledge of Zoro's techniques should allow him to anticipate it and avoid it.
In terms of Kenbunshoku usage they're both on the same tier, Zoro's buso is more potent and advanced and Sanji currently lacks any Haoshoku at all.
Honestly their versatility and combat skill could also be analyzed to see who's superior but with what I've currently brought up I feel Zoro wins this, so I'll vote for Zoro.
Since you already showed Zoro's reasons, I'll be doing it for Sanji now:
In terms of Kenbunshoku I'd say that Sanji may be better than Zoro, similar to Zoro buso's being better than Sanji's. So in terms of speed and Kenbun Sanji has the right hand here. Plus Sanji has better overall mobility with Skywalk, which would help him a lot, since it'd difficult to Zoro to tag him in the air, even using his long-range attacks it would be hard, because he'd have to hit it, which is not goin to happen.
And in the same way Zoro's heat resistances would help him mitigating some damage of Ifrit Jamble, Sanji Exo-Esqueleton would help him a lot when resisting Zoro's attacks, since he could reinforce even more his skin with busoshoku, albeit his busoshoku being inferior to Zoro's. For this we have that moment where his Raid Suit was unphased by King, which is a pierce attack, but now after his awakening his resistance is far better than before.
For Sanji's attacks I don't have much to say, Ifrit damage would cause some really good damage on Zoro and with a better mobility + Kenbun, he probably would land more hits on Zoro. Albeit one hit of Zoro could be equivalent to all the damage caused before, I think.
In terms of skill they're equivalent, I don't think Sanji outskills Zoro, neither Zoro outskills Sanji, which makes this fight even better. The Zoro advantage would be the Haoshoku infusion, that would be able to cause some considerable damage to Sanji. I my opinion this fight could exented a lot, to the point where their stamina would dictate the result, but they're also comparable since now Sanji became one of the Germa monster, so seeing him tired is almost out of cogitation.
Since I'm fan of both characters I'm not voting for now. But since they're even in a lot of terms an incon is plausible in this match, or even a double K.O. Anyways, I don't know if Kachon will comment, but this is my guess.
