settlements of Chaco Canyon in New Mexico

The first theory in reading paragraph says that the Chaco structures were residential. However, though it may seem from outside a plausible explanation, upon closer look it does not seem very convincing. It seems that not many people lived there. If hundreds of people were to live in these houses, the houses should have had many fireplaces. This has found not to be the case.
The second theory is that the Chaco structures were used for storing food supplies. But this theory is not supported by enough evidence. For, excevation did not find reamins of maze grains or containers which could contain the grains.
The third and final theory proposed in the reading paragraph is that the Chaco structures were ceremonial centers. But a lot of stuff which one does not expect to find at ceremonial center, like construction material, has been found at the site. The presence of large number of broken pots, which was considered as supporting evidence, could just be some trash from construction. Thus all the three theories appear to be very weakly supported.