Griffin01

As far as I know, more guns per turret did result in increased space and weight efficiency. However, they were quite a bite larger than dual mounts, which should be reflected in the game. As for lack of use of triple or double secondaries, I'd say it was more because the secondary battery was often used for DP guns, and going above double mounts resulted in poor AA effectiveness. The only exception to that rule that I know of were the Germans, who used a turreted SP battery in double mounts for their batteleships. Else, if you wanted a dedicated turreted SP battery, you'd go for larger turrets. I could have missed some cases, though