Why triple five-inch mounts struggle as fast-tracking weapons

What other US ships might receive the triple five-inch mount if North Carolina scheme C were built?

Ideally none; the mount's extra crew and handling complexity would make it worse for rapid secondary and anti-aircraft work than distributed twins.

North Carolina preliminary scheme C provides the counterfactual starting point: eighteen five-inch guns in six triple mounts. Triple mountings become more attractive at cruiser gun sizes, while destroyer and secondary batteries must track fast-moving targets and move their crews with the weapons. Adding a third gun and its handlers can crowd the mounting enough to erase the advantage suggested by the gun count. British experience with triple four-inch mounts supplies the warning example, with three twins considered substantially more useful than two triples.