What forty County-class cruisers do to treaty fleets

How would a forty-ship County-class program change treaty limits and Axis naval strategy?

It would raise cruiser allowances, give Britain denser escort and hunting groups, make German raiding much harder, and force an already infeasible Plan Z to grow further.

If forty County-class ships existed before the London negotiations, their tonnage would become the practical ceiling the British sought to preserve. The United States would claim comparable heavy- and light-cruiser totals, with Japan receiving its negotiated fraction. German raiders would then face mixed groups containing several heavy and light cruisers instead of isolated opponents. France and Italy might be allowed more ships on paper, but their industrial and financial capacity would determine how many appeared. The scenario also makes solitary carrier movements such as Glorious's final voyage less likely because enough cruisers exist to provide escorts. Plan Z would have to expand massively to answer the larger British cruiser force, even though German maritime infrastructure already made the historical plan infeasible and left Britain able to outbuild it repeatedly.