Ross Perot never came close to winning a single state in 1992. The only ones where he even came in second place were Maine and Utah. He would need to win dozens of states to get enough electoral votes to win.
I'm not sure how anyone can believe that a different running mate would have made a huge difference.
FWIW, I lived in a MA town where Perot did win in his first attempt. So I saw first hand how community attitudes can move. I really think that what held a lot of other places back is that Perot didn't choose a viable VP.
People were really upset at NAFTA back then. Us "little folk" were right, and what is DC doing? Manipulating ways to vote for more anti-US worker trade deals while still getting re-elected.