I think you misunderstood me...
No, I think I do understand you, I just object to the way you are expressing the idea. You don't want to actually keep science and history out of your fantasy - which is probably impossible. You just don't want your imagination to be constrained by science or history.
I understand, but I suspect that is a groundless fear. Science and fantasy don't constrain fantasy or the imagination, they in fact inspire it and enlarge its scope.
First, fantasy (and, on a broader term, speculative fiction) tends to be much more about popular imagination than really History itself. There are numerous historical mistakes in the popular conception, along with many concepts impossible to work in real-world Physics. People still like it because it’s cool.
I agree with that, and did agree with that, when I noted that things like Druids were in fact based on nothing more than imagination that became mistakes in the popular conception, and in turn inspired many other secondary creations. But the person that knows both the popular conception and the historical truth has grander scope of their imagination and more understanding of the possibilities than someone who knows the popular misconceptions alone.
However, when someone starts to brag about how ninja and samurai were so different in medieval Japan, how a given weapon is impossible to exist in real-life, how many things were different in their original conception, it’s time to stop and think.
Indeed, it is time to stop and think, which is exactly my point. And among that stopping and thinking is considering how the inevitably richer and more complex reality might inform the limited imagination of popular conception with its trite simplicities, mistakes, and absurdities. The truth is that no one's imagination is so unlimited as to create a work as complex, detailed, sophisticated, coherent, and imaginative as the collected imaginations of everyone else who has ever lived. You'll never have the time to exceed the creative endeavors of all the architects, painters, jewelers, and story tellers nor conceive of anything as grand as the actual real tapestry of history. So to banish that from your mental efforts is not to increase them, but to diminish them. You need all of that history and stuff to flesh out and inform your work, and without it your work will be small and tawdry.
Historical/scientific accuracy are good only as they improve our work, by being just cool and (in games) by gameplay. The exact moment they start being “Stop Having Fun, Guys!” is the moment we threw them in the trash can.
This is a strawman argument. No one is suggesting that you don't have fun.
Third: Gameplay. We already have a Shaman class. If people want a Witch class, then surely people want something at least a little different from the already-existing Shaman.
We don't even need to appeal to history to suggest the danger of that. We need only appeal to gameplay. An endless variety of classes don't improve gameplay. For example they create problems of balance and place a greater rules burden on the table by creating endless supplements filled with classes that only diverge from other classes in minor details. "There is more than one way to do something" is not necessarily to the benefit of a system. Further, a multiplicity of classes makes Chargen more challenging while not necessarily increasing creativity. Indeed, at some point, more classes reduces creativity rather than enhances it. A good example would be the handling of Prestige Classes in 3.X where most of the Prestige classes were rife with play problems that varied from poor balancing to severe front ending to being simply a fixed list of powers that had to be taken in a fixed progression to actually specifying the characters personality, background, and type to the point that every member of the prestige class was fundamentally the same character.
When I suggest that the Shaman is a better choice than the Witch, it is precisely with the intention of increasing fun rather than decreasing it. Green Ronin's shaman is a master piece of configurable design that allows you to create all sorts of different sorts of characters with very different flavors. It lets the player call out their own powers and restrictions to suit the sort of character they imagine, and it is almost infinitely extensible by leveraging common game elements (such as clerical domains). With a bit of configuration I used it to replace the Druid class entirely, not because I thought the Druid anti-historical or because I wanted to put a kibosh on the popular imagination, but because the Druid as implemented in the RAW was bad for gameplay - a poorly balanced jack of all trades, master of all, that could overshine whole parties of lower tier class characters.
My problem with the 'Rule of Cool' is that it rarely advocates for things that are either fun or cool. Besides the fact that what is 'cool' is purely subjective, so that I could equally argue from the 'Rule of Cool' for strict historical accuracy if I was a mind too (and I'm not), but the 'Rule of Cool' tends to actually be in practice 'this is what should happen because this is what I imagined should happen'. It's predictable and trite, and I doubt I'd have a lot of fun as a player if 'the rule of cool' was some guiding principle. You can't boil down story, plot, challenge, and so forth to 'it's cool' except in the most tautological of manners.
If electronic RPGs depicted the full hygiene of the Middle Ages, for example, people would literally vomit before the screen.
Contrary to popular myth, the people of the Middle Ages were very clean and bathed regularly. The Age of Dirt and the abhorrence of bathing followed after the Black Death that ended what we now call the Medieval culture, and among other things closed the public baths common people depended on for hygiene. It was the Early Moderns in the 15th and 16th centuries that were foully stinky and dirty, though I suspect the tolerance for that sort of thing in depictions is higher than you think.
And I’m pretty much done with this. There isn’t much more to be said. If this line of thought won’t convince you, someone like me also won’t.
Don't let your imagination be constrained to only what happened in history. Don't deprive your imagination by starving it of the very fodder it needs to create things that are truly original, unique, and "Cool".
