the dirty little secret of ToEE is that the actual dungeon was sort of precedurally built by Gygax for his kids to play around in and wasn't ever really going to be a commercial product, but people reacted so well to T1 The Village of Hommlet and constantly wrote into Dragon Magazine requesting the full dungeon, that the company felt like they had to release something, so Gygax tasked Frank Mentzer to flesh out it from his copious stacks of notes, because he was so busy trying to run the business side of D&D, and was out in Hollywood trying to negotiate film deals and handling the cartoon, etc. The bottom line is that ToEE is a really crappy example of a dungeon; it's linear, it doesn't make a whole helluva lot of sense, and it's a slog. I was always surprised that ToEE got adapted into a CRPG, because it was always sort of looked at with mild disappointment by the people I gamed with in the mid to late 80s..