Replacing the Hawkins class before the next war

When should the Hawkins class be retired, and what should replace it before the next war?

Around 1932, followed by continued County-class construction.

Retiring the Hawkins class around 1932 would leave enough time to continue County-class construction before another major war. The timing matters because the Royal Navy could use an established cruiser programme instead of improvising replacements after hostilities began. A later retirement would preserve the older hulls but shorten the period available to build and work up their successors. The practical answer is therefore an early-1930s disposal followed by more Counties.