^I don't think that changes anything. I never said she wasn't
talking about Mitchell; obviously she was. But the gist of her sentence was about how long Kirk and Mitchell had been friends and colleagues. And yes, the E could've been Kirk's first command, but if that were the case, it wouldn't actually be relevant
to the point she was making, so there'd be no reason for her to use such an incredibly awkward and convoluted way of referring to the ship they were both currently aboard
. She just would not say it that way unless she were talking about an earlier ship at some point in the past.
And really, why resist that idea? What's wrong
with the idea that Kirk had an earlier command, especially when we know for a fact that it's what the show's creators intended and have absolutely no evidence to refute it? It's by far the more probable interpretation of Dehner's line, and I see absolutely no reason to object to it. There was never any indication in TOS that Kirk was an inexperienced commander. On the contrary, he was portrayed as a respected, seasoned career officer despite his relative youth.