As a former AA analyst, I thoroughly studied the implementation of rolling hubs in the early 90's. (It was abandoned at that time because we needed short connection times to get good display in the travel agent's reservation systems.)

Truly, you can only implement rolling hubs in the busiest hubs -- that are near peak capacity. Otherwise, your connecting times will be much too long. For example, even with AA's saturation at DFW, connecting times for mid-day connections from San Antonio to Seattle are as long as 2.5 hours -- a bit long for my tastes.

Rolling hubs do require fewer aircraft and also improve crew utilization -- by minimizing downtime of aircraft and crew. For example, rather than waiting at a "spoke" station for 2 hours for the next bank of flights at the hub, the aircraft will return to the hub immediately (after a 50-55 minute turnaround time).

In some sense, rolling hubs are how Southwest has "connections". They just schedule a lot of flights into a city (say Las Vegas, Phoenix, Baltimore, Houston Hobby, Chicago Midway, Nashville, St. Louis, Kansas City, Dallas Love, etc.) and connections tend to "naturally occur".

One caveat is that rolling hubs cause the airport to be moderately crowded for long periods of time. In the early 90's, before DFW was remodeled, we were literally simulating unusually long lines for the restrooms and restaurants!