pvebber,

What do smaller ships buy you? The advantage of the US aircraft carrier is that it can carry a large number of aircraft and size influences stability in rough seas. Are you thinking something more along the lines of a modern equivalent to the WWII escort carrier?

I also don't see how retooling to more, smaller ships, mitigates the threat, especially in light of the downsides to a more numerous, small-ship fleet.

And again it's important to point out that the "book" technical specifications and capabilities for threat systems only provide part of the story.