Are we going to throw in the N3s too?For a strategic sort of warplanning and fighting, I agree the USA would likely remain in enclosed homewaters, or near the coastline most of the time, to lure in the opponent. This was not teh discussion however. The discussion was on the sorts of ships and their value in regular combat. In this case the South Dakota class of 1923 was seriously inferior to the G-3 design in every aspect, appart from having more guns. Basiccally it was almost stationary steel fortress, that was difficult to move opposing to a much more mobile, more heavily armored tank. A speed difference of 8 knots is a serious problem here, as the faster side can make choices what to do and the slower cannot.
Hypothetically the USN as planned would compose of six South Dakota's, Four even slower Colorado's and four, or perhaps six fast Lexingtons, with no armor to speak of. That is ten slow modestly armored battelshisp and maximum of six very fast, alsmost unarmored very, very large ships, all with 16 inch guns. By this time the Royal Navy could easily have created its own first 4 G-3 ships, perhaps more. The first to engage eachother were the Scoutgroups, supported by the fast 16 inch gunners, like at Juttland the Scoutgroups were the first to collide. Both were based on light cruisers and destroyers. Here a significant advantage for teh Royal Navy, sicne teh USN lacked light cruisers in the first place. (Just the Omaha class present around this time of 10 ships, devided over two oceans!) Let's assume half is present at best, due to Geopolitcal demands on two oceans, these will first face a much larger number of British cruisers, mainly of C and D type, perhaps a few E type as well, and perhaps even some early Kent class as well. Also the Destroyer number favours the british here, with more and better seaboats than the USN flushdecked four stacked DD's. These light forces will first slug it out against eachother and the numerical advantage of the Royal navy will start to tell soon. Supproting 16 inch fast ships will come into play soon as well, shooting mainly at eachother, while smaller ships duke it out themselves. The oversized and very weakly armroed Lexingtons cannot sustain hits of large calliber shells, just as Beatty's ships could not at Jutland. We might see some going up in the air quickly as a result. The much thougher G-3 can sustain hits quite well, especially when handled well, meaning bow on to target at sharp angles.
So the USN scouting group is wiped out as a fighting unit after this, unable to continue fighting as one organised group. The main battleline is now blind as a bat, unaware of what is comming and from where. Though having relatively more firepower to the older British main battleline, it had lost the scoutingforce and intelligence. The British scoutingforce is still intact and also still maintains her big G-3 type ships, that were hardly damaged in the fight, due to more experience in naval shootouts. These ships will also support the main battleline against the enemy line. (British DD's had the upperhand at sea, so could finish off crippled enemy ships easily with torpedoes. Crippled giant thinclads were likely to attract such attention. See Battle of Matapan). The resulting cannonade of big guns vs big guns is more like the blind man fighting the one eyed older, more experienced guy. Thogh having older ships in general, the Royal Navy can score hits in battle, while the Blinded USN line, with no asset of modern firecontrol and radar, cannot do on equal terms. Also the pesky seaworty British DD's keep launching torpedoes at them at the same time, where the USN DD's were scattered already after the breaking of the scoutinggroup. With no cruiserprotection, the USN line is very vulnerable against torpedocraft, while the Grand Fleet maintains its cruisers to defend against DD's. Outcome: Tactical win Royal Navy.
Or are we just going with more G3s?