Why maximum turret redundancy becomes a very large ship

A battery divided among more turrets can keep more guns firing after individual hits. From that narrow survivability perspective, an extreme American-style six-turret, twenty-four-gun design has a rational purpose. It only works if the navy has infrastructure able to build the hull and machinery able to give it useful speed. Guns already consume most of the design's weight, while armor, barbettes, propulsion, crew spaces, and superstructure remain to be added. The armament choice therefore pushes displacement and the rest of the ship upward together.