One can make a case that Kirk’s first command is referenced in WNMHGB. Dehner mentions Kirk asking for Mitchell when he received his first command and that can be interpreted to mean one of two things: the Enterprise is Kirk’s first command or he had a previous command before the Enterprise. I think the latter holds more weight as it makes more sense for Starfleet not to hand command of one its frontline ships to a neophyte, and it gels with the reference in Kirk’s bio.
Yeah, that's more or less the rationale that
@Christopher used in his recent book
The Captain's Oath, which covers Kirk's command of that previous vessel (the
Sacagawea, in his book) and how Kirk became Captain of the
Enterprise.
In my head canon, I believe that:
1) Kirk commands that destroyer class vessel at age 29 the rank of Commander (the Saladin, in my mind).
2) Kirk is promoted to Captain when he receives the Enterprise assignment, which is part of why that command is so special to him.
3) Commander Kirk asked for his friend Gary Mitchell to serve with him on the Saladin, but...
4) Mitchell couldn't accept because he was already serving aboard the Enterprise under Captain Pike (circa 2263-2265).
5) Kirk then is promoted to Captain at age 31, becoming the youngest Academy graduate to do so, breaking Christopher Pike's previous record of making Captain at age 32.
I believe that this reconciles all of the information from both TMOST and WNMHGB. Kirk had a previous command before the
Enterprise, but he doesn't become a Captain at an implausibly young age. Kirk asked for Mitchell on his first command, but he didn't get him, and Mitchell still served next to Mr. Spock "for years", as Dr. Dehner says during the WNM briefing. And I personally find it
very intriguing to think that around the time of WNM, Gary Mitchell knew both Spock and Kirk better than they knew each other.
