Why Perry-class frigates belonged inside the task group in high-threat waters

Why not send an Oliver Hazard Perry-class frigate by itself into the highest-threat area?

The proposed approach assigns the independent high-threat mission to a Burke. Perry-class frigates remain within task groups in a war zone, where they still contribute.

A Burke is the suggested choice for an independent mission in the highest-threat area. Perry-class frigates would receive missions appropriate to their capabilities. Under this approach, they would operate within task groups if conditions left no low-threat area. They remain important to those groups even when going out alone would be unsuitable.