Could the Royal Navy have introduced the 15-inch gun before the Queen Elizabeth class?
Short answerPossibly in an earlier battlecruiser experiment, but the Queen Elizabeths were the earliest practical program.
NotesThe Queen Elizabeth class is judged the earliest practical battleship programme for Britain's 15-inch gun. An earlier battlecruiser offers a possible route to introducing it slightly sooner. The answer does not support a broad earlier introduction across the battle fleet.