Also, with those in the East who did move about, it was within a certain territory that they held.
For example, Lenape would leave Manhatta for Long Island in the summer because it would get too hot, and returned during cooler weather to live the rest of the year.
They never sold it to the Dutch for $24 worth of beads, they loaned it to them temporarily. At least that's what they thought they did. They found out rather violently that that was not the case in the eyes of the Dutch.