When a separate ship type justifies its production costs

Repeating one design simplifies shipyard work, supplies, and crew training. Every additional type introduces another set of requirements in a war where sustained output matters. That cost can be justified by a capability the existing ships cannot provide: carriers and destroyers remain necessary despite their differences. Alaska faced a harder case because her 33-knot speed, 12,000-nautical-mile range at 15 knots, and heavy firepower overlapped with ships already entering service. More battleships were being built than Alaskas, even though the cruisers were supposed to supplement the scarcer capital ships. As the fleet shifted toward carrier warfare, fast battleships also took over the escort work that might have distinguished the large cruiser.