I have to admit I have never build anything above 15k tons, the larger ones in my example have only been thrown together in the ship design window to get the numbers, so I have no real experience with large ships.
That being said, I also have not realy thought the thing through from that angle, thanks for lighting me up
I might have to reconsider my design philosophy (which currently is/was: smaller is better)
On the other hand, I have to look realy hard at what the advantages/disatvantages of large BBs vs. more numberous CA/CL are
The main advantage of larger ships is in economies of scale. For example, Aurora calculates the amount of armour required on the basis that ships are spherical. As the size of a sphere increases, the ratio of surface area to volume decreases. In other words, a 50,000 ton ship with strength-4 armour uses less armour than five 10,000 ton ships with strength-4 armour. Sensors (and to a lesser extent fire control) are another area where you save mass as the 50k ton ship will only need one set of sensors compared to five sets for the smaller ships. Having five smaller ships means more flexibility in terms of deployment, smaller maintenance facilities and cheaper development costs for systems such as jump drives. As with many other things in the game, it will depend on your situation and your general fleet design concept.
Steve