Thats all your own assumptions moron. Youre making excuses about zoro being nerfed. No one uses their strongest attack at full strength. They will always be at their last breath when they use it. Stupid
Now you seem all riled up and I am sorry I'd I hurt your feelings, didn't know you are so attached to Luffy and your crusade against evil Zoro fans.
Now lemme ask you a question
Have you read arlong park? Zoro could barely do any damage to Arlong because of how nerfed he was.
Zoro was so nerfed he couldn't even move and all of Zoros power comes from physical strength and Haki.
Now lets make a logical assumption but before we do that lets remember the provided context and work with few facts we have.
So first Zoros dialogue to Law
"I will put all my remaining strength into one final attack since I am nearly at my limit"
So the context here is that what ever remaining strength Zoro has in his severely nerfed 30 broken bones body he will put into one attack.
Which he did and he only had enough strength left to do significant damage damage Kaido and scar him but not "Take Kaido down with himself" like Zoro wanted.
Now I would assume if Zoro didn't nerf himself by tanking Hakai Ashura would have taken Kaido down.
Current Zoro should be able to take Kaido down in one or two attacks tho.