If you want to know the reason that there are no examples of the Brooklyns, ask the British.
As well as despatching the last example of the Brooklyn class to the bottom of the South Atlantic, the RN's view of the usefulness of the 8" armed cruiser can also be seen in its building plan - 6" cruisers were definitely favoured over their bigger-gunned cousins (especially when available in triple turret form).
Another snippet to remember is ammunition stowage. A cruiser typically carried 150-200 rounds per gun. With a theoretical ROF of up to 10 rounds a minute (or even more for short periods) that would equate to fiting off the ship's full load of ammo in about 20 minutes which is (IIRC) about 5 VAS game turns (don't quote me on that - I've worked out the duration of the turn based on gun range and ship movement but its too early in the morning to remember the answer!)