The comic or original ghostbusters script had him as a scientist but they flip it. I'm not sure about where it came from but I know the original intention for that character
Fukk I lied I looked it up. Originally Winston's name was Ramsey and he was just a security guy who joined the team and that's when they wanted Eddie to play him. Then they took the security angle out and made him an Air Force vet trained in karate and an accomplished cat who would just be the audience's surrogate. It's canon now that he got his doctorate (which is in the comics) as that happened between ghostbusters 2 and the dope ghostbusters video game