I think there is no logically coherent scenario, based on their respective feats where Zoro would lose to Luffy in a fight.
For starters his Gear 5th mode while dancing around Kaido's blunt attacks, took damage from a cutting attack as remarkably weak as Wind Scythe.
Zoro's cutting attacks are in the worst case scenario at least 1000 times stronger than that.
Secondly Zoro's CoA barrier and overall Raw CoA level is a lot stronger.
And while Kaido (before even revealing he has Future sight since Luffy fans use that argument a lot) had no issues reacting to snakeman. Kaido was completely perception blitzed by Ashura while 30 broken bones.
Not to mention Snakeman has no reaction speed feats to dodge something as huge as Tatsumaki and his barrier can't block it as Luffy was struggling to block even one wind scythe with his barrier.