Re: Did McCoy also graduate in 3 years?
in the comic about McCoy he was already a doctor, he hadn't intended to work in the space his career and plans for the future were to live his life in earth. Then his wife wanted a divorce and it changed everything. In the comics he also meets this kid who is one of his patients whose dream was to join startfleet but doesn't get the chance.. so McCoy basically gets the idea to join it himself from there...
Then like some people already said here, it's pretty possible he graduated sooner because he already was a doctor.
Spock: I apologize, Captain, but the complexities of human pranks escape me.