but Gilliam was a hired gun on that movie more than an “auteur,”

If you’re using “auteur” they way it is used in “auteur theory” then I disagree. Part of the entire concept of auteur theory is that directors working within commercial systems that don’t give them full control can still make films that are idosyncratic and personal because they exercise authorship through the way that they actually direct the film. I’m not saying that it excludes films where directors have more control. The same set of critics that popularized these ideas championed Citizen Kane as the Greatest Film Ever.

But yes, I understand your point, he was hired onto a project that was somebody else’s idea and he didn’t write the script.

I remember 12 Monkeys as a movie that people were still talking about in the early 2000s, and I mean “still talking about” as opposed to “discovering after they got into film.” It was a Hollywood movie with big stars and a cool weird ’90s movie that everyone has seen. Maybe to college kids who are interested in that sort of thing now Time Bandits, 12 Monkeys, and Brazil all have the same level of visibility, but if that’s true now it wasn’t always true. I also remember Fear and Loathing In Las Vegas being popular at that time. No idea if people who didn’t grow up with that one care about it now.

but that’s not as weird as her being a $cientologist and acting on a show that did that “Movementarians” episode, which was pretty clearly an attack on $cientology.

It probably resembles other cults more than Scientology, although I haven’t seen that episode in a long time. Scientologists know that Heaven’s Gate was a cult. They don’t see Scientology the same way.

but aren’t they basically both just Clint Eastwood?

Yeah but Damnation Alley has the aesthetics of post-Apocalypse in leather jackets. Nearly every discussion of Zelazny’s story makes the comparison. Weirdly, George Miller claimed never to have read it.

I’d never heard of Damnation Alley, which seems to me like a really stupid version of Sorcerer

It’s not that much like Sorcerer. I guess the book is more like Sorcerer than the actual movie, since the book gives them an actual mission. There’s a Hawkwind song about the book, btw.
It’s one of the worst movies I’ve seen in the last 5 or 10 years, and it’s really only interestingly bad in the sense that it’s hard to comprehend why they though the changes they made to the original story were a good idea, or how anyone expected it to be more successful than Star Wars.