Carrier groups are described here as having five assigned cruisers and destroyers, against roughly three times that number in the 1970s and 1980s. Assigned ships can also be hundreds or thousands of miles away on other missions. A nominal escort allocation therefore differs from a nearby protective screen. The comparison depends on distance: a carrier a couple of hundred miles away can provide aircraft and other support, while a more distant carrier cannot be assumed to offer the same coverage. In this interpretation, the shortage of larger escorts helped drive the requirement for Burke-like capability in Constellation.
Notable Point · 1:34:44-1:37:37
Detached escorts and Constellation's capability requirement
A carrier group's assigned escorts may be serving elsewhere, leaving a frigate with less immediate support than the fleet list suggests.