The resorts fill much more quickly than the parks do. The resorts fill up first, to 85% - 90% occupancy, at which point it becomes very difficult for people like
@ThatMouse to find availability for their specific dates. This is the "base case" scenario that plays out pretty much year-round. The fluctuations in attendance are (primarily) not driven by resort guests, since the resort guests are always there. The fluctuations in attendance are from local guests and off-property guests.
Yep. Lower crowd levels mean that reduced staffing is 100% legitimate. It doesn't mean the operation is under staffed, it just means the operation needs less people (or less hours) to be "fully staffed" when the crowds aren't as high.