Hermit crabs fighting over the biggest house on the block

Spotted this group during low tide on the Brewster Flats in Cape Cod, MA. Tidal flats that go out for miles, leaving ankle deep water as far as the eye can see. These guys were going at this for at least 5 minutes straight, but it seems like the clearly biggest one had it in the bag. Hermit crabs kept coming and going. At one time, there must have been 20 all in a stand off in a circle.