Hunts were build BEFORE the DEs.
They were planned as fast escorts, more with focus on AA and shallow water combat than on ASW.
Basically:
Type I: Planned with 3 4" twin mounts, but a terrible calculating mistake jeopardized the stability of the ship, so one gun mount had to be removed.
Type II: Stability corrected, but 3rd gun mount replaced by torpedoes.
Type III. Three gun mounts
Type IV: much improved with different hull shape, 3 gun mounts and torpedoes.
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