“I was trying to express frustration with the fact that a lot of anarchists only seem to gain scholastic inspiration from members of the scholastic anarchist tradition”

Well, sure, this is a genuine problem.

“The indigenous inhabitants of North America, while not Utopian (there is no such thing as a Utopia) were a good example of what could be described as “anarchism”, or at least something very close to it.”

Some of them were and some of them weren’t. You’re talking about an entire continent’s worth of people over a period of tens of thousands of years, who ranged from nomadic hunter-gatherer bands, to roving warrior-bandits, to settled stateless confederations with complex social structures, to rigidly authoritarian terror-empires. Some of them are good examples for anarchists to study and take lessons from; others clearly are not. The idea that “the indigenous people of North America” are some homogenous block that exemplified anything in particular at all is precisely as silly as the idea that “the people of Eurasia” are.