Step-by-step explanation:
One of the main reason for the evolution of the depiction of the Native America in film, showing from gentle character to sometimes a savage warriors who attacks people and does massacre on the people by the filmmakers is they able to reach out the mainstream audience, mainly the white audience and to the generalization of the Native American cultures.
The reasons why Buscombe deals and cites when he tries to explain how the filmmakers want to define the two different kind of of Native Americans.
They shows how the Native American people helped the "white people" and how they went against and refused their own people for the white as they are the ":good" Native American.
And there is the other Native American people who went against the "white people" and they tried to stand by what they have faith in was depicted as a savage kind and "bad" Indian.