This is a really interesting subject and a great topic for research. I agree completely with the basic thesis: the mendicant life is, at least in part, modeled after the “simpler” and “purer” lifestyle of indigenous peoples, many of whom still existed in the Buddha’s day.
You might want to also look at some of the legendary suttas like the Agganna and Cakkavattisihanada, these contain descriptions of lifestyles with these elements.
There’s also a lot of relevant material in the Jatakas. For a non-Pali example, check out the following:
