My thinking was 8 guns was OK v a
10 gun Italian (rebuilds) or a 6 gun German (pocket BBs) and that speed (and better deck and DP guns) would be much more useful as she will anyway not be useful v a slow strong battleship anyway.
Note she is not that serious and would only make sense in a treaty limited world where MN had to counter the Italians and Germans (and maybe IJN Kongo's) without new builds.
ed should look facts up before writing
Still think in early 1930 the threats to the MN are a pocket battleship (6 x 11') or later Scharnhorst (9x11') or a rebuild Conte di Cavours /Andrea Doria (10 x 12.6') both would be matched by 8 x 13.4'. But they would need more than 21Kn (to catch a raider with 27 or 28Kn or 31Kn) so swapping out the turret should allow us a good 31Kn.