British battleship gun development in 1.5-inch steps

If Britain built American-style battleships, would their guns progress through 12, 13.5, 15, 16.5 and perhaps 18 inches?

That would fit the British practice of increasing calibre in 1.5-inch steps, partly to avoid accelerating the technical arms race.

The suggested sequence follows the British practice of increasing main-gun calibre in 1.5-inch steps. Moving from 12-inch to 13.5-inch and then 15-inch guns fits that pattern, with 16.5-inch or 18-inch weapons proposed as later possibilities. The measured increments also limited pressure on the technical arms race. No definite construction schedule is established for the hypothetical ships.