I never noticed at first because I got into the whole FF7 series about two years after the films release.
But after some browsing (due to boredom) of Zack's English voice actor, I was looking at where else he has been a voice actor / acted and I saw Transformers (2007) on the list.
I watched the scene from Transformers with the Sheriff and I was like "OMG It's Zack!" xD
He really sounds like Zack when he says: "Goofballs" and "What was that?".
Check it out if you hadn't noticed before hand! x)