If they knew anything about cinema, they'd know that it was actually a rip-off of Three Amigos! (everyone in town dressing the same to confuse the villain) - which itself was spoof of several films including the Magnificent Seven (the cowardly townfolk finally helping the heroes) - which was itself adapted from the Japanese film Seven Samurai - which itself was adapted from stories read by Kurosawa - with a bit of High Noon (lone Doctor facing the villain at noon) and a smattering of High Plains Drifter (stranger arriving out of the blue and saving the town) for good measure.
The fact that the villain was not (entirely) human was all-but irrelevant to the setting - it just made for interesting visuals whilst adding a sci-fi twist with the story of why he wanted revenge - unlike Westworld (and Futureworld) where the entire plot hinged on the inhumanity of he androids.
If any film could reasonably be compared to Westworld, it would be Jurassic Park (same writer, same plot but substituting "badly designed" dinosaurs for badly designed machines) - but all of them can be said to have been lifted from the far older stories of "The Mummy" which also centres around people using modern technology and ignoring warnings that they are crossing a line in terms of messing with something "fundamental" - thereby releasing a killer that pursues them relentlessly.
(Apart from that, if they ever do another "A good man..." type episode where the Doctor calls in a few favours and needs some help, I'm voting right now for the Gunslinger to be one of his posse)
PS - A good man goes to war is very VERY much "an homage" to The Magnificent Seven.