I still feel as though Shadow Lord was basically a mish-mash of elements that Laurence Yep enjoyed, with the "Star Trek" label slapped onto it, though.
Well, that's kind of what makes it interesting. Star Trek
has always had room in it for a wide range of different types of stories; keep in mind that the original intent was to make it a framework for an anthology-style approach to storytelling, since the starship could take its crew to any kind of environment the writer could conceive. If there's room in the ST format for haunted castles, gangsters, ancient Romans, and so on, there must surely be room for feudal societies and swordfights as well.
Yeah, this is particularly notable in early TOS where you can see them experimenting with different types of storytelling from episode to episode: a monster movie, a submarine thriller, a courtroom drama, a morality play about a fugitive war criminal, a murder mystery, etc.