^But there's no reason to call it "Ceti" anything unless it's located within the Cetus constellation. The word "Ceti" has no meaning besides "of Cetus." So regardless of word order, "Ceti Alpha" is going to mean "the Alpha star of the constellation Cetus," and that's Alpha Ceti.
In fact, in Vonda N. McIntyre's novelization of the movies, she corrected Ceti Alpha to Alpha Ceti.
And who says TOS wanted to avoid disparities with real astronomy? They constantly used the names of prominent real stars: Rigel, Vega, Antares, Deneb, Aldebaran, Capella, Canopus, Altair, Arcturus, Izar, Merak, Regulus, Alpha Centauri, Pollux, Omicron Ceti, Gamma Hydra, Gamma Trianguli, Epsilon Indi, etc. And they quite commonly put inhabited planets around stars that are too young and hot, or too far past the Main Sequence, to support them, since they went with well-known stars and those are usually the abnormally big, bright ones.