My wish is that you could select the type of turret housing you want for your guns: larger turret housing would take more space but it would give faster reloading, more ammo and better accuracy. This way you could put 6 inch guns into a larger turret, similar to what we see on the Jean Bart, instead of going for 8 inch guns or something.
I mean, I'm not sure if there are any examples of 8 inch secondaries being used in Battleships. 8 inch shells are absolutely massive for hand loading after all.