The Black Swan distributed-fleet concept's magazine problem

How useful would a modern sloop be for securing trade routes?

It could be useful, but a distributed modular force needs enough hulls and missile depth to sustain its promised capabilities.

The Black Swan concept used a distributed network in which modular ships divided air-defense and other roles across a group. The design looked flexible when each specialist hull was considered in isolation. It became less convincing when measured as a sustained fighting force, because roughly sixty Mark 41 cells spread across several vessels provided little magazine depth. Distributed capability still has to be tested against numbers, reloads, losses, and the need to keep the network functioning.