Unified secondary guns save more than mount weight

How much weight could a unified secondary armament save?

The saving is cumulative across mounts, magazines, directors, ammunition hoists, crews, and the spaces needed to support them.

Gun standardization is a whole-ship systems decision. Fewer mount types require fewer specialized magazines and ammunition-handling paths. They also reduce the number of directors, crews, accommodations, and support arrangements carried throughout the hull. The benefit is therefore much larger than simply subtracting one gun mount from a drawing. Mixed batteries impose hidden displacement and personnel costs.