The maximum ranges of 6-inch and 8-inch guns differed more than their effective ranges in visually controlled combat. At practical engagement distances, a 6-inch battery could put more shells and explosive onto the target because it fired faster. Damage to the bridge or fire-control equipment could blind the opposing ship and produce a mission kill. A torpedo-armed cruiser could then close to finish the disabled opponent. The attraction of rapid fire depended on those expected fighting conditions and the ability to exploit the damage.
Notable Point · 16:17-17:26
Why 6-inch guns could win a visual cruiser engagement
Rapid 6-inch fire could disable a cruiser's bridge or fire control within visual fighting ranges, creating an opportunity to finish it with torpedoes.