Complex sentence: The story and the teachings of the Great Peace belong to all Iroquois people, not just the Oneida people, and this rule of law, indigenous-style, was open to all who chose to fall under it.
Split into simpler sentences: The story and the teachings of the Great Peace belong to all Iroquois people, not just the Oneida people. According to indigenous tradition, this rule of law was open to all who chose to fall under it.