Would retaining sloops and similar small ships have helped the Royal Navy at the start of the Second World War?
Short answerYes; a larger small-ship reserve could have eased the escort shortage and reduced the need to divert resources from larger warships.
NotesThe argument is about timing and capacity rather than a single perfect ship. Sloops and similar vessels below the major treaty thresholds could enter anti-submarine and convoy service without consuming the resources of a new fleet destroyer. More ready small escorts would reduce the emergency shortage that otherwise diverted yards and equipment from major construction. That could bring big ships into service sooner while giving convoys more protection during the dangerous opening phase of the war.