But I was already annoyed by a ground battle description. So, there are only male security officers. No women, no aliens. On the 23rd century Starfleet flagship.
That's consistent with what we always saw in TOS. We never saw a female security guard, or an alien Enterprise
crewmember other than Spock, until the animated series. First Strike
is set in the early second season, after "Friday's Child."
I admit that I cheated and added a female security officer to my next TOS book, but, yeah, Spock is clearly the only "alien" officer aboard the Enterprise
in in the original series, given the way his Vulcan nature seems to be a constant source of interest and curiosity from the rest of the crew. One gets the distinct impression that Spock is regarded as something of a novelty by the otherwise human crew of the Enterprise.
That being said, I suppose it would be possible to have an alien Starfleet officer or diplomat be temporarily assigned to the Enterprise
for the length of one book . . .