Six-inch Bristol-class cruisers and the later Towns

How would nine 6-inch guns on the Bristol-class cruisers change the later Weymouth, Chatham, and Birmingham subclasses?

The later Towns would likely retain 6-inch guns and shift innovation toward torpedoes or twin mounts that could also reshape the C-class cruisers.

Later Towns would probably standardize on the 6-inch gun if the Bristol subclass began with nine of them. The 5.5-inch weapon is explained as a Vickers sale for Greek orders that Britain later acquired and liked enough to fit to Hood. With the main caliber already settled, the counterfactual offers more room to pursue heavier torpedo armament. Twin 6-inch mountings are another possibility. The answer distinguishes those mountings from the twin turrets adopted historically and suggests that earlier twin mounts could substantially increase the firepower of later C-class cruisers.