US Navy and British Royal Navy chose for 15cm/6” guns as main armament for their light cruisers according to the Dutch magazine Marineblad dated 1938 no. 7

An item referred to the U.S.R. dated 13 October 1938 reporting that regarded the armament of the American Phoenix-class light cruisers (5x3-15cm/6” guns) the American and British navy were obvious similar minded in appraising a larger number of 15cm/6” guns above a smaller number of 20,3cm/8” guns.