In my opinion, there are several significant errors. One error, which stems from modern social conventions, concerns the portrayal of natives from tropical regions.
It's common to see native women in those films wearing bikini-style garments that cover their chests. Historically, this didn't happen in any culture I'm aware of.
In ancient times in tropical areas it was usual to either go bare-chested or use a type of poncho or blanket over them, but not triangular pieces of cloth over the breasts.
It was also much more common that if a genital covering was worn, it did not cover the rear.
In many cultures, men went completely naked, as did unmarried women.
What we see in movies is a sanitized image according to what is considered normal in Western culture (covering the breasts, genitals and intergluteal area).
Depending on the region where the film takes place, there are different examples of what would be considered authentic attire, for example below.
Representation of a Malabar couple (India)
Representation of ancient Taino indigenous people
Representation of Tupinamba indigenous people
Aboriginal people of Australia
Representation of Selknam indigenous people of Patagonia
Guarani Indigenous people
Clothing styles of Mesoamerican tribes