It is certainly true that much of our mythology about the Pilgrims and the Indians feasting together at harvest time in the 1620's is not quite right. Multiple events have been fused into a single story, and some of the difficult bits have been taken out. The cooperation and bonhomie were likely related to the near-starvation of the early settlers and the horrendous death-by-disease which many of the northeastern tribes experienced just prior to the arrival of the Europeans and all their cool technology. Sometimes groups turn on each other in such situations, but for others, mutual benefit can be a bond, even among people who have little intuitive understanding of each other.
There is a dramatic truth which does emerge from the story, however. For fifty years they lived together in remarkable peace. Compared to how people were getting along back in England, and England vs Continental Europe, the Puritans now had remarkably good neighbors. Compared to the tribes inland, the Mohawks vs the Iroquois Confederacy and even some of the very local other tribes in Massachusetts and Rhode Island, the natives around Plimoth enjoyed comparative peace as well.
There were terrible things done, more by the Europeans to the natives than the reverse but not all one-sided. But as is often the case, many Massachusets or Wampanoags considered the English safer and more reliable than Mahicans, while the English in their turn liked those natives better than the Dutch or French traders that happened by.
There is another revealing point as well. Bradford and other diarists record that when the groups got together, the younger people had competitions and games, the women compared various works and skills of hand, and the adult men sat together and talked. Race and religion are perhaps not as reliable dividers of people as sex and age, at least in social situations.