The cheif difference between the Thermian approach and the Brandon approach is source material. Thermians, have ONLY the aired material to draw from, while Brandon also has the books The Making of Galaxy Quest
and the Galaxy Quest NESA Protector Technical Manual
and other items of backstage research to draw from to help fill in the gaps. However, the Thermians must make their guesses without this supplemental material.
Although Galaxy Quest
is a clear analog of Star Trek
there is one rather huge difference... that being that somehow the aired episodes of GQ defined a consistant enough ship that both the Thermians and Brandon & Co. managed to arrive at such similar deck layouts. I imagine there must have been an episode where the main viewscreen displayed every deck in succession in one scene and that someone behind the scenes on the show made sure the locations for things in the hull stayed consistent... something which no one on Star Trek
really spent too much time on. At least not any any real depth....