Using Invincible as the treaty cruiser standard reshapes every ship category

What would cruiser design look like if HMS Invincible set the Washington and London treaty standard?

Heavy cruisers would become small battlecruisers, forcing every lower and higher category to expand and changing carrier and battlecruiser force structure.

The counterfactual builds an entire treaty ladder from Invincible: roughly 40,000-ton capital ships with 18-inch limits, 17,500-ton heavy cruisers with 12-inch guns, larger light cruisers, and a distinct destroyer-leader tier. Those fast heavy cruisers could scout for carriers or combine with retained battlecruisers in powerful task groups. The later follow-up explains that treaty totals would still be aggregate tonnage allowances rather than a requirement to build every hull at the maximum size. Britain could choose somewhat smaller 12-inch cruisers and gain additional hulls, but could not shrink them so far that they ceased to compete with foreign ships at the ceiling. The alternative treaty therefore changes not only individual designs but also fleet numbers, industrial workload, and the balance between concentration and coverage.