Tbh, Dragonball is at some points inconsistence as fuck, so every fight could be debatable.
One problem with Nappa is his charakter. He underrated his enemies, that´s why Krillin nearly killed him with his destruction disc. Fodder like Yajirobe could cut Vegeta his tail of, when he was off guard. I think Zoro can hurt Nappa, since Zoro should be scale far above Yajirobe, but i didn´t see any chance for him if Nappa rampaged with his fingers, or his Mortal Kombat style. Zoro dies the second, if Nappa gets pissed off. We should let him fight against weaker and slower DB charakters first, then we could say if Zoro wins or not.
If Zoro is bloodlusted and Nappa in charakter, he could win. If both are bloodlusted then Nappa stomps hard. If both are in charakter, then Zoro attacks him, Nappa dogdes probably to late and get hurt by Zoro. That is the moment that Nappa is pissed and blinks Zoro horrible.