That groups migrated all over is scant surprise either as that entails meet and greet and passing through until you possibly found a stretch of unoccupied country with welcoming neighbors. Such units would not be seen as a threat so much as a fresh ally against enemies.
What we are seeing is dispersion using canoe transport. This is easily enough to move a family band across the Caribbean and into the coastal littorals.
Thus we have far more mixing than ever assumed and much greater potential mobility.