Why not build Indian County-type cruisers with triple six-inch turrets?
Short answerBecause triple six-inch mountings were not yet available in the 1920s, and Washington placed no overall limit on the number of eight-inch cruisers.
NotesA proposed Indian County derivative with triple six-inch turrets is anachronistic for the 1920s. No triple-six mounting was then available in the British system; HMS Enterprise's experimental installation used a twin turret. Washington also imposed no overall numerical ceiling on eight-inch cruisers, removing the later treaty incentive to trade gun size for more hulls. Town-class-style triple-six arrangements therefore belong to 1930s technology and policy rather than the immediate post-Washington choice.