How armoured cruisers might have evolved without the treaty compromise

Did Japanese heavy-cruiser tonnage resemble the armoured cruisers that might have evolved without naval treaties?

Potentially. A true armoured-cruiser lineage might have produced less compromised ships with roughly 9.2-inch or 10-inch guns.

Japanese cruiser size potentially approached what armoured cruisers might have become without treaty limits, provided classes such as Warrior or Duke of Edinburgh had set the design lineage instead of Hawkins. More displacement would have reduced the compromises forced on a large light-cruiser hull carrying 8-inch guns. A 10-inch weapon might have defined the upper category, although its weight and handling would make it awkward. British designers in particular might have preferred the familiar 9.2-inch solution. This is a counterfactual use of historical design families to explain what the treaties displaced.