What people don't understand is that no one is claiming Zoro is below or even as strong as Killer or something. He was matching KIller just fine with nitoryu and Oda had to use an excuse for Killer to land the hit(distraction coming from the fox), and did manage to one shot Killer afterwards with santoryu, but the fact is that his endurance display at that moment was very pathetic and there is no excuse about it, with the stomach ache excuse reminiscing the Sanji-Usopp level injuries that were up to date in the Vergo debates, which sounds like a great amount of double standard
Zoro has always been weak to peircing attack.
This absolutely do not change the endurance feats that he has shown against slashing and blunt attacks. But some people absolutely want to brush off all of Zoro’s feats during the totality of the story because of that (especially the TB’s one).
Why it is different for Sanji? Because:
-Sanji never has his legs bone broken before Vergo
-Sanji’s legs are supposed to be the strongest part of his body
-If Zoro’s swords would have been broke or receive a nick it wouid have been on the same level of Sanji’s broken leg.