What a successful dual-purpose mount might have changed

If the 4.5-inch dual-purpose mount had worked as hoped, destroyers could have answered dive-bombing threats without hurriedly removing 4.7-inch guns or torpedoes to fit four-inch anti-aircraft weapons. The Royal Navy was already exploring dual-purpose mounts as its understanding of air attack moved beyond interwar assumptions about high-level bombing. Success with a five-inch mount might also have opened a route closer to an Atlanta-style cruiser rather than the 5.25-inch Dido solution. Mount scarcity limited Scylla and Charybdis to four twins instead of five and influenced the enlarged superstructure around them. One failed weapons programme could therefore redirect destroyer refits and the design of an entire cruiser type.