How older 12-inch capital ships would serve in a later war

Without the First World War, what roles would Britain's 12-inch dreadnoughts and battlecruisers have in a war beginning around 1936?

The battleships would shift to Channel and other secondary duties, while the faster battlecruisers continued global-presence and surface-raider missions.

The older 12-inch battleships were aging but still useful second-line units. They would probably follow HMS Dreadnought into the Channel Fleet, where numbers and heavy guns remained valuable without exposing them to the most modern enemy battle line. The 12-inch battlecruisers could retain their original global-presence and surface-raider missions because speed still gave them operational reach. Some battleships might also reinforce operations against the Ottoman Empire or support French and Italian forces against Austria-Hungary.