How a scout-carrier category could expand the Royal Navy

What if the First London Naval Treaty created a separate 15,000-ton scout-carrier allowance?

Britain could build a mixed fleet of about twelve light and fleet carriers instead of concentrating its tonnage in only five large ships.

The counterfactual treaty provides separate allowances for light scout carriers and larger fleet carriers. An illustrative arrangement assigns 75,000 tons to ships capped at 15,000 tons and 150,000 tons to larger carriers. Britain could use the light allowance for six roughly 12,000-ton ships derived from Hermes, accepting a smaller individual vessel to gain another flight deck. Six 25,000-ton fleet carriers could use the larger allowance. That gives about twelve ships for worldwide duties, compared with the five 27,000-ton ships that would consume a 135,000-ton allowance. The argument concerns geographic coverage: maximizing each carrier's size can leave too few hulls to serve all the required stations.