Why modern escorts combine primary and secondary roles

Why not build more mission-specific ships instead of expensive multi-role combatants?

Specialists create fragile task groups and still need broad escorts; primary-role ships with useful secondary capabilities provide resilience when assets are lost or detached.

Single-purpose ships leave a force brittle when one specialist is lost, detached, or disabled. Historical anti-submarine escorts still carried anti-aircraft guns and surface weapons, and they normally operated beside destroyers, carriers, and cruisers rather than as isolated one-role hulls. Modern Royal Navy types have primary roles plus useful secondary capabilities: Type 45 emphasizes area air defence, Type 26 anti-submarine warfare, and Type 31 general-purpose presence. Type 31's 57 mm gun and two 40 mm guns are also assigned a point-defence role in front of a principal asset, concentrating gunfire against an incoming attack. That breadth lets each ship protect itself, contribute outside its specialty, and reinforce a task group without requiring the fleet to fund a separate complete escort for every mission.