Fantasy does NOT have to follow real world rules. Fantasy does NOT have to relate to some real world event, country, concept, law, or history. Fantasy does NOT have to mirror any particular time period or country, even if you’re basing your world on a real world one. There is NO SUCH THING as “historical accuracy” in fantasy as it relates to the real world.
THE ONLY THING Fantasy has to do to be believable is follow the established rules OF ITS OWN WORLD. Fantasy can literally be anything you imagine it to be.
If your fantasy world excludes people of color or those belonging to the LGBT+ community, if it’s grossly misogynistic and white cis-male centric, that’s because YOU made it that way. Stop blaming “historical accuracy” or “believability”. It’s not the genre; it’s YOU.
if there’s chimeras and gorgons and shit, there’s no reason the world can’t have LGBT members.
Hell, especially if the monsters are greek or roman because the greeks and romans were hella gay. like, achilles and ajax were super gay for each other so even if you do want to be “accurate” to world history, remember that LGBT members have ALWAYS existed.