That's kinda a thing in a lot of genres, though, innit? An idea bounces around and collects a bunch of different spins?
(And drug-naming is something of an art.)
I would say that the superhero genre is extremely blatant with the knock-offs copying one specific original. It is often very easy to directly identify who is a generic form of someone else.
Contrast this to sci-fi. A lot of stuff is a rip-off of Star Wars, but there's also a good amount of Star Trek and a few others (Dune, etc). Most knock-offs are at least a little bit of a blend. Ditto with horror, where the knock-offs often intentionally blend more than one source together. A lot of broader genres, like action blockbusters or (going old-school) westerns are much more decentralized, so the knock-offs tend to resemble a lot of big names at once rather than being a direct copy from one specific source.
The only other genre I can think of where it's so blatant who's the original that's being copied is kids stuff. The low budget Disney and Dreamworks knock off videos make zero attempt to hide what their ripping off.