To speak of some pre-European “Native American lifestyle” is more myth than reality, when it comes to the Native American cultures and allegiances of the many ethnic groups which inhabited North America before the Spanish, British, French, and other European colonizers came here.
In reality, Indian (the preferred terminology within most Native American cultures and ethnic groups even today) bands and tribal groups were as diverse and fragmented in their culture and their alliances with each other as were any of the nations of Europe. The Iroquois Confederacy of the Northeast was a major exception to this. The five original “nations” or tribal groups which made up that alliance (Seneca, Cayuga, Onondaga, Oneida, and Mohawk) — joined by a sixth (Tuscarora) in 1720 — were a major exception. In those regions we generally refer to as the Old West (the Plains and the Southwest), there were some 30 distinct cultural/linguistic Indian groups at the time of earliest contact by Europeans. In Mexico, Central America, and South America there were many, many more.
Native American cultures diverse, population estimates uncertain
Population and tribal group estimates for the entire pre-Colombian Western Hemisphere are guesses at best and range from 10 million to more than 110 million. Recent scholarship tends toward the 10-20 million range. It has also been estimated that there were as many as 300 distinct American Indian language and cultural groups in North America in the year 1500, the designated starting point in many history books for European contact.
Among the many distinct tribal groups there were indeed alliances, mostly those of convenience for food gathering and hunting purposes. There were also constant and bitter wars, rivalries that extend back for centuries. In some cases among the Plains Indians in particular, there were tribes with common ancestry which became historic rivals after they were split apart by invading groups from outside the Plains. (One excellent book, though somewhat dated now, for learning more about American Indian history and culture is “The American Indian: Prehistory to the Present” by Arrell Morgan Gibson.)
So there was little cultural or linguistic unity among the 300+ American Indian tribal groups here when Europeans came to the Americas. And those alliances which did exist were often easily broken if that meant beneficial trade and treatment with the invading Europeans. We cannot possibly understand the history of the Old West without understanding more of the cultural diversity and dynamics of the Native American cultures which were here when Europeans first encountered them.