Bucky's arm is made of metal. Drax ripped apart an industrial strength prison riot bot. He's basically outside of Bucky's strength and ability to hurt seriously. And he's pretty skilled, he takes fight 1.
Round 2 probably ends with Drax bloodied, but I think he wins too. A much better fight than Round 1 though.
I know Drax should win based on his stats and all, but he just didn't seem that impressive in his movie. I mean, most of his h2h fight scenes were against fodder and that drone he tore apart... do we have a concrete example of how tough they were?
Cap tore a thick log with his bare hands and it didn't even look like he was trying. I'm not saying that's as impressive than Drax tearing the drone but WS has a robotic arm that's stronger than Cap and quite lot more displayed speed and skill than Drax.
I'm unsure about the first round but the knife fight should go to WS.
Korath was a Kree just like Ronan. And Drax took him down. Drax also shrugged off having his head used to bust apart some stone, as well as Ronan crumpling industrial grade metal around him.
He can tank pretty much anything Bucky throws, because Bucky's arm is not stronger than Ronan.
In the knife fight, Drax has more scenes using his and he's got a much longer reach on account of being bigger and the knives being more similar to short swords, while Bucky had a tac-knife with a much smaller profile. Also his knife slashes were sending guys into the air.