The problem with oral histories is that they can be untrustworthy, particularly when there are few sources.
Listening to an ad on TV about our local Indian tribes and their casinos, I heard a bit about their long traditions and noble behavior and how they loved the land and lived in harmony with nature or something like that. It was all traditional Native American hagiographic claptrap. Triggered by my reading of Churchill's A History of the English Speaking People, which is blunt and straightforward, I began to wonder just how much of what we take for granted about American Indians is true.
Without writing, how much of what they "know" about themselves is accurate? How far back can reliable memory go when it's all handed down by story?
Imagine what the stories would have been like had Hillary Clinton been a Kumeyaay Chieftaness around 1200, prior to the arrival of the Conquistadores. She'd have run the tribe out of a server in her own teepee, sold out their interests for heap big wampum from neighboring tribes and then unleashed her own storyteller flacks to create utter nonsense about how she was noble and good and aligned with the planet and everyone who disagreed with her was part of the Vast Apache Conspiracy (VAC).
With a sufficiently effective terror apparatus, Chieftaness Hillary would have been able to make sure that only her versions of "history" survived.