quite the opposite when it comes to kaido.. who time and time again prove less evasive so sudden attacks.. like killers, kid's. luffy's.. zorovs tatsumaki.and law's surgery . the onky reason why kaido dodged zoro's slash before hand was coz BM told him....Kaku is not kaido he ain't a mountain..
The original comment was the philosophy of being big you are percieved as an easier target to hit is false. Another example is Oars, big but moves fast. Same philosophy applies to Kaku a lot bigger so Zoro thought he could easily hit his next, but that was wrong. Same thing with Kaido in dragon form