My problem with the Cloud-Zack connection in Crisis Core is that Cloud was indeed pragmatic, arrogant, and quite the sarcastic anti-hero from the start of the game, and that persona really only broke down after Cloud's recovery from Mako poisoning and he realized who he was again. After that, Cloud, while still being a little snarky was way more similar to how Zack is portrayed in Crisis Core. When Cloud finally regained himself, he was a little more goofy, a little more kind, and a lot more optimistic (which completely through me off when I watched AC for the first time).
If Cloud really took on Zack's persona at the end of Crisis Core he would have acted like Zack to begin with, and then changed into his own personality at the end. Instead, it seems Cloud's personality at the end is more similar to Zack in Crisis Core.
Quoted for effing truth. I keep saying the same thing. If anything - in the original, pre-memory fix Cloud has more in common with Sephiroth than with Zack, making the comparison between Cloud and Zack utterly bizarre.
This is probably true. Though I also think that a lot of people just sorta forgot what Cloud was originally like playing the game.
Time passed, people played FF8 and FF9 etc. and the only memories that stuck with them from FF7 were naturally the most iconic ones, like the death of Aerith etc. where Cloud is, understandably, very emotional and very sad. Those scenes though, conspire to render their impression of Cloud as being largely emotional and sad as a character when they can't remember any of his other traits.
I'm playing the OG in Japanese on my PS Vita right now, and there, it's more obvious than ever that pre-memory fix Cloud has absolutely nothing in common with Zack what so ever. If anything, compared to the western localization, Cloud is a real jaded a-hole. His speech pattern, and sociolect shows him as often being condescending and mean - like a less slang-ridden Barret and less swearing Cid, but just as abrasive but without "a heart of gold" to compensate for it like the two other characters. It really isn't except when Tifa calls up memories of his old self, or when Aerith starts kicking on his heart-strings that Cloud shows any signs of being anything more than his SOLDIER persona in the beginning of the game.