Strange Adventures in Film Adaptations

You know when you're watching a film based on some other source material and you notice that something got changed in the adaptation process? Most of the time you can see why the filmakers might do sometihng like that. For example, Iron Man's butler Jarvis sometimes comes of as an Alfred rip-off so they turned him into a talking computer for the movie.
On the other hand, sometimes the changes they make seem so arbitrary you wonder what happened behind the scenes.
For example, take Arnold Schwarznager's Conan films. The movie is cheesy but most of the time the character rings true to the source matrial. He is regonisably Conan.
The problem is the film's villain "Thulsa Doom". I put that in quotation marks because the character in the movie is clearly not the Robert E. Howard creation Thulsa Doom.
The simple way of putting is that Howard's Thulsa Doom is supposed to look like and indeed, may be the inspiration for this guy--- (I used the live action movie beacuse that's about how the special effects for Thulsa Doom would have been at the time).


This is the character we actually got.

Ignore the havy metal soundtrack. It was the best video I could find.

Anyway, the problem is not that they changed the character for the movie. It's that they gave took a completely different Conan character and gave hime the name "Thulsa Doom." However, the character that shows up in the movie is clearly inteted to be Conan's other recurring nemesis Thoth-Amon. Like the films' "Thulsa Doom", Thoth-Amon was an African sorcerer with a snake obsession. (He also, despite widley being considered Cona's arch-nemisis, only ever actually directly fought the Barbarian in the later, non-howard penned stoires, but that's neither here nor there).
I can literally think of no reason for this name change other then the producers though that "Thulsa Doom" sounded more menacing. However, one could argue that it is a minor nitpick that is uttely unintegral to the final movie and that I'm just being pedanitc here. One would probalbly be right.