Perhaps that would be the case today when there are sub categories for everyone. However, when the film was made back in 1984 guys were considered jocks or nerds and both Booger and Lamar would be considered nerds. I graduated high school in '92 and back then there were only a handful of guy groups in my class. There were the football team and their friends (the jocks), the black kids and their friends and the nerds/dorks. There were a couple other random cliques like the actors who all hung out together, but most of them would be considered nerds/dorks.
I also graduated in '92 and they would not have been considered Nerds in my school. Our class president, and now Navy Colonel, was a gay black dude, who threw sick parties. Everyone had to go through him to hook up with the "hot" chicks.
The guy you are talking about from high school wasn't a nerd then, that's kind of the point. The guy you are talking about was part of the cool crowd obviously or people would be interested in going to his parties.