Neil Patrick Harris makes Colonel in about a year?!
I think this movie starts with their first invasion and then says "One year earlier...". going back to when they are graduating.
Neil Patrick Harris heads off to military intelligence - presumably not as the sole recruit for that particular year.
By the time the brain bug is captured - on their second mission (some time but clearly not years after that initial failed mission) - he's strutting out in his gestapo jacket as a Colonel!
How exactly could this have happened?