Britain was winning the naval race without exhausting its capital-ship building capacity. Armstrong, John Brown, Fairfield, Devonport, and Palmers are among the yards named, while some capable yards lacked enough orders to stay solvent. That spare capacity would let Britain build a second 15-inch Tiger even in a scenario where Germany added another Seydlitz. A 13.5-inch Tiger would join an existing group with that battery, whereas a lone 15-inch ship would be the only battlecruiser providing its particular capability. The comparison with the original decision to order two Lions supports building the new type as a pair.
Notable Point · 1:08:24-1:10:41
Why a 15-inch Tiger would need a sister
Spare British yard capacity and the Royal Navy's preference for a usable pair make a second 15-inch Tiger more plausible than a lone experimental ship.