An interwar sloop-building counterfactual

If the Royal Navy understood convoy protection, what should it have done differently before 1939?

It should have funded a steady annual sloop program from the late 1920s, potentially producing a large mature escort force before war, even though governments instead relied on rapid wartime expansion.

The Royal Navy had escort plans and relevant design experience, but started its buildup roughly a year to eighteen months too late. Matching destroyer construction with annual sloop orders could have produced about 180 escorts over a decade and driven several generations of design improvement toward Black Swan-like ships by the mid-1930s. The counterfactual also raises treaty and signaling consequences: such a large British sloop force might have looked like destroyers built through a loophole. The funding choice belonged to several interwar governments rather than Churchill alone.