PJDQ, I'm not ignoring you, I'm trying to ascertain the correct answers for your questions, which are reasonable queries.
The best I can do about why the seeming duplicate sub-categories exist is simply that each editor probably had a similar idea and created a sub-cat for it. I'm not going to stifle their creative spirit and tell them they can't do it; I'm simply going to suggest they coordinate their efforts and try to avoid direct duplication.
Why they got to different places? Again, more than one editor in a category will have a different idea of where to send something. I don't expect them to coordinate on every quiz; they'd be bogged down completely. However, there's no reason you, as the quiz creator, could not query the editor directly from the quiz about this and ask that they at least be put together in one place. You'll find our editors are very nice people and quite responsive to recommendations from players and quiz creators.
I'm sorry I don't have something more definite for you, but I won't make an authoritarian site out of what is intended as a fun area. I assure you the players will find your quizzes, no matter where they are, and are quite used to searching all the areas that fit their particular interests.
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Gunslinger