> For example, the army, FEMA, etc. will ship in nurses

Might ship in more nurses, and until they do, the beds that can't be staffed don't count towards capacity.

> 50% occupancy

Having the capacity to staff those beds is not the same as the beds being occupied. Beds are occupied by patients, not nurses.

ED nurse here. Of course n=1: "can be added" doesn't means "will be added". Our ED regularly boards admitted patients to the point we have a single resuscitation room left for new patients checking in or coming in via EMS. Plenty of rooms and physical beds in the hopsital, and by official metrics hallway beds are counted in "beds available". We did have National Guard present for some time, but it was non-clinical warm bodies to sit with patients on suicidal precautions, stock supplies, etc. No extra clinical staff. Though they were incredibly helpful and lightened the load, they did not enable more beds to be available.