Why one frigate hull produced several classes

Why did the Royal Navy build several different frigate classes around the same period?

They used a standardized hull but specialized individual classes because the hull could not accommodate every role and system at once.

The family of postwar frigates began with a common hull and a limited internal allowance. Designers assigned different sensors and weapons to different ships because fitting every role into one hull was impractical. The result was several classes that shared a physical basis while dividing tasks across the fleet.