Would Britain have benefited from completing more C-, D-, and E-class cruisers after the First World War?
Short answerYes, especially as replacements and reserves, but the extra ships cost money the Treasury and Navy chose to spend on other priorities.
NotesThe Washington system did not prevent Britain from completing additional cruisers in these categories, so the proposal was legally possible. Extra C-, D-, and E-class ships in service or reserve would have helped replace aging wartime cruisers and expanded the pool available for conversion or secondary duties. The obstacle was financial rather than conceptual. Every additional completion competed with higher Royal Navy priorities for a Treasury unwilling to fund the whole desired program.