I have to admit, I've always found X-Ship-Navy plans to be a bit odd. They begin with a number of ships and then seek to fill the number (e.g. 'more smaller ships'). Which is exactly backwards. We ought to ask how many of each role we need, and calculate back to total force.
Oh, sure. It just seems like once the number makes it out into the world, it is the number, no the force structure which is treated as holy. The core problem is that we're trying to design a force structure without having a serious discussion about what that force ought to do.