I have my doubts about Zoro "besting" the Hybrid form. It wasn't made clear what that deflection really was; did he deflect Hybrid Kaido's attack or did he just deflect a still standing club to have a good shot at his body. With Kaido not really caring about Ashura as he believed he will take it easily.
Compare it to Kaido going serious and using Haoshoku barriers.
Kaido's arms and the club are in the air so he is preparing to slam down on Zoro and gets blitzed in that moment.
The clashes before blitz suggest that Kaido has put up a haki barrier in front of himself and that's what Zoro is clashing with.
Either way, Zoro has bested Kaido in close combat and worked his way up to a clean hit, it wasnt for free like in Oden's case.
The aftermath of the impact gives us a clear winner. Also, Oden's scar looks huge while Zoro's looks like a small extension of Oden's scar. Kaido collapsed to the ground after Togen Totsuka but was still standing after Asura. Asura was strong, but inferior to Togen Totsuka for now.
The size is pretty much the same if you realize that Zoro's scar doesnt begin where Oden's ends but begins from the intersection of two lines from Oden. The aftermath is simply due to storytelling, that was the last thing Oden ever did to Kaido, if Kaido shrugged it off like Asura then Oden has achieved nothing which isnt an option for Oda who wants to hype Oden up.
Once Zoro is done with Kaido he wont just collapse, he will die.
The difference between Asura and Paradise Waterfall is simply the dramatic storytelling requirement in Oden's case.
The scars are pretty much the same and in case that Zoro didnt even use CoC, it is looking even more impressive.