How the Hawkins class set an outdated treaty-cruiser template

Was the Hawkins class already outdated by 1922, and how did it influence treaty cruisers?

Yes; its design had aged, but its existence made it the practical template for the treaty definition of a large cruiser.

Hawkins began as a large light cruiser intended to help fill the gap below increasingly expensive battlecruisers. Its open 7.5-inch mounts are judged outdated even before the class became the benchmark for later treaty cruisers. The alternative discussed is a more powerful modern armored cruiser with 9.2-inch guns, a design path that Britain did not get to pursue. With Hawkins as the largest existing cruiser, the Washington negotiations instead used its size and armament as their practical reference. The later London treaty placed eight-inch cruisers in the heavy category, changing the terminology applied to ships conceived as large light or scout cruisers. A final counterfactual asks whether six-inch Hawkins armament would have lowered the limit, or a 12,000-to-15,000-ton ship with 9.2-inch guns would have raised it.