What's odd about that? Saavik apparently went from an officer cadet to chief science officer on USS Grissom. And she didn't even save the entire planet from a terrorist attack!A fair example of something that is unbelievable in nuTrek is Kirk being promoted from a third year cadet to the Captain of the flagship of the Federation.
More to the point, the fact that Kirk kept screwing up is the main reason he wound up getting demoted. If Pike hadn't vouched for his abilities -- TWICE -- he never would have made it on the Enterprise at all.
And STXI went into why Kirk wound up getting command: because Pike himself had hand-picked him to command the ship. STID shows us it's a decision that Pike came to regret as Kirk really WASN'T ready when he took command and on some level even he knew this.My point is, if you're gonna present something, present it in a believable way. Spock throws Plomeek Soup at Nurse Chapel, that would be considered unbelievable under normal circumstances, but since the episode gets into why he's acting this way, it's perfectly believable.