The only attack you can really argue that with is the post timeskip upgraded version of sanzen sekai. An attack that zoro basically said he had to use hardening to protect his blades
No other attack pre dressrosa or even pre timeskip did zoro even imply his attacks were too much on his swords
No other attack pre dressrosa or even pre timeskip did zoro even imply his attacks were too much on his swords
Pre-skip Zoro was getting too strong for regular swords well before the timeskip.