I was pretty surprised they had Kirk going for Admiral so early in his career, but I ended up liking that whole story line, so I as bothered once it got going.
Everything is accelerated in the Kelvinverse. In the next movie (set a couple years later), Kirk would be transported into the 24th century where he'd be killed falling off a bridge. Spock would then scream "IT"S BEEN FUUUUUUUUNNNNNNNNNN!!!!!" (just to add a twist on the scene).