alt Hacker NewsVery broad strokes. "Indians vs. Whites".
But the Roman situation was more akin to "what precisely happened during the Thirty Years War". I really like history, but I wouldn't be able to tell you if Münster or Würzburg sided with those or these.
Unlike the conquest of North America, which usually resulted in physical destruction of the Indian tribes and their displacement by the colonists, Roman conquests tended to absorb the conquered polity, often with the basic social structure still intact, so the nobility would remain in local control, the priests would remain priests of that particular local god etc. This tends to take the edge off and make assimilation easier.
The conquest of north America was largely done by smallpox. As soon as the Europeans arrived, it doomed 95% of the population, who had been spared countless plagues and viruses that swept through Asia, Africa and Europe over the millenia. This fractured many tribes and collapsed their numbers to a point where they had no meaningful polity, maybe a few hundred to a few thousand at most.
Among the remaining tribes and the decimated numbers, many did in fact eventually integrate with Spanish, French, or English settlers, particularly the tribes that allied with them against another rival tribe, such as the Tlaxcalans who aided the Spanish in conquering the Aztecs, and subsequently integrated.
We hear the most and remember the most the tribes which warred the most fiercely (ie Commanche, Apache, Sioux, etc), however, we scarcely remember the tribes they themselves slaughtered, enslaved, and scalped, such as the Crow and Pawnee (who would ally with the US Army) . And some like the Iroquois were generally peaceful and continue to this day.