J.T.B., there is no comparison. A Navy ensign could not save the world with an aircraft carrier.
But if for some reason, one did, what would you suggest the Navy do with him/her? Promote them to Admiral of the Fleet?
There have been instances of one person, or two, doing a deed of this magnitude. Google the name 'Stanislav Petrov', for example.
I'm mellowing a bit on this whole Kirk thing. For a few reasons:
- Kirk wasn't a cadet, he was a Lieutenant. He was, technically, graduated, but this was held up because of the cheating thing. I believe this is made clearer in the novelization. Also, in TOS, Kirk graduated with that rank as well.
- Spock Prime was very insistent that Kirk should be captain, even though it's 2258 and I doubt Kirk of the prime timeline was captain by then. In any case, Spock probably imparted a fair amount of command knowledge via his mind meld.
- I never considered Admiral Pike's role in this. If Kirk's rapid rise to the captaincy was Pike's idea, I'm cool with that, I guess. Pike knows Kirk better than anyone. If Pike thinks Kirk should be captain, I trust that judgment.