Was the adoption of triple turrets on Royal Navy cruisers still a long way off?
Short answerNo. They were considered for the Arethusa and Amphion classes before being adopted in the Town class, the next major cruiser group.
NotesThe Royal Navy considered triple six-inch turrets for both the Arethusa and Amphion classes. The Town class followed those discussions with an actual installation. The interval between considering and adopting the arrangement was therefore comparatively short.