True, WW2 era cruisers were 6000-13000+ tons (DANFS has USS Atalanta at 6000 and USS Baltimore at 13600 tons). Aside from the Atlanta class, "light" and "heavy" referred more to the gun size than the displacement. E.G. CL Brooklyn displaced slightly more than CA Pensacola.
The treaty limit was 10,000 tons although frequently cheated on by several players, and the only difference between light and heavy was the gun size, 6" for lights and 8" for heavies. The CL Brooklyn, for example, was identical to the CA Wichita except that the CL had 5 triple 6" turrets and the CA had 3 triple 8" turrets (The first of a newer 8" that fired a significantly heavier shell than the US treaty cruisers); naturally there were some internal differences in armor distribution with five main turret barbettes in the CL rather than three in the CA, but if anything that meant the CL might have had a slight edge in weight (Official figures on ship weights are basically unreliable for any class initiated prewar since the US was one of the players who lied extensively on it, both for treaty and domestic political reasons, just not to the extent the Germans did). The Japanese Mogami class CLs made it even simpler, their 5 triple 6" turrets were simply replaced one-for-one with 5 twin 8" turrets when the Japanese shitcanned the treaty. The limits technically went out the window when the Washington Treaty expired, and the war program production was not limited by number or tonnage, just price tag and resources.
The dominance of carrier warfare rapidly changed the role of cruisers and much of what they did pre-war is now in the province of ship types other than cruisers.
