what i think hes referencing isnt cloud being a Zack rehash, its the whole Zack did this thing first, like the falling through the church for example, this was a unique moment cloud had that SE made Zack do first, and they went and called it an homage to the original, which i call bull on that one
It wasn't SE, it was Nojima who created the original plot point of falling through the roof. So him calling it a homage would make perfect sense.
and Aerith wasnt attracted to Cloud just because of Zack, not only because of their contrasting personalities, but because the scene she makes a reference about Zack, she says she was bothered by how the way he walks and gestures being similar to Zacks, but that hes different and that things are different
That's if you get high affection points for Aerith. Otherwise she don't say that, and you can assume that she was originally taken by how Cloud's situation was so similar to Zack.
also, cloud never took Zacks personality in the game, and his whole fake persona are based on other factors, as in, tifas memory of cloud, clouds ideal self, clouds own personality, and cloud memories of Zack and superimposing himself into Zacks place
He didn't take his personality completely, but he took his memories, and thus apart of his persona, along with a bunch of other factors. That doesn't invalidate the point, that he superimposed himself onto Zack and thus became a portion of Zack for a time.