Dave Shoup
Banned
Guns and turrets have a longer lead time. The 15” turrets require updating and that also requires gun pits already used for new build 14” turrets. 6 15” guns is a really sub optimal solution. The Vanguard was only seriously considered once war was certain.
War was pretty certain in 1937. Likewise, if the 15/42 guns and turrets historically reused for Vanguard (and, for that matter, Roberts and Abercrombie) were in good enough shape for those three newbuilds, all laid down in 1940-41 in wartime, presumably they were in good enough shape for one or two newbuilds laid down in 1937...
Given that the British had all of 15 capital ships at the time, of which 2-4 would be in major rebuilds through to 1941, one or two modern ships in service and operational in 1940 sounds more like a godsend than anything else.