Why F3's dockyard and ammunition needs matter against G3

Why would G3 be less useful to the Royal Navy than F3?

G3 would be harder to dock, supply, and modernise, while its greater gun calibre is judged to offer little practical advantage over F3's 15-inch/50 weapons.

F3's smaller hull and 15-inch armament would fit the Royal Navy's worldwide support system more readily than G3. The larger G3 depended partly on dock improvements that did not go ahead, limiting where it could be maintained. Its amidships turret is also criticised for complicating later anti-aircraft upgrades. Nelson and Rodney illustrate the ammunition problem: their distinctive 16-inch shells had to accompany deployments, while 15-inch ammunition was widely available. The practical difference between a 15-inch/50 and the proposed larger guns is judged small compared with these support costs. G3's greater nominal power would therefore require additional investment to match F3's strategic usefulness across the empire.