Taiwanese think it’s the same animal? 
There are many ‘squid like animals’ that are eaten in Taiwan and no they don’t think they are the same animal. Wu zei are cuttlefish and Hua zhi are squid. There is also You Yu.
Zhang Yu is octopus. Anyway while I’m not very clear myself on the breakdown I know many people can identify them , at least the dead ones!
the soup made with either is very very tasty and one of the dishes i really miss over here in the bay area!
Why some like to eat’em i got no idea-. They don’t have any sort of real flavor until they start turning bad and the texture is something between gluten and rubber