This seems about right, even if the Navy focuses exclusively on low-end ships in a high-low strategy to get hulls in the water:
The latest attempt to bridge the gap between the 350-ship vision and political and industrial realities is a hybrid plan that mates accelerated shipbuilding with service-life extensions of existing hulls. This plan, which calls for building 27 additional ships over the next decade while upgrading existing ships to extend their service life five to 10 years, could bring the fleet up to about 350 by 2030. While perhaps the most realistic plan, Congress is still no likelier to appropriate the extra $150 billion it requires, and inexperienced shipyard workers are still likely to cause delays.
We could get additional numbers and a surge capacity by building mission packages of anti-ship, ant-submarine, and anti-aircraft, and land power projection capabilities (and others) using standard shipping containers as the building blocks to make modularized auxiliary cruisers from container ships.
(As an aside, I'd love to see a UAV carrier version.)
I wrote about the value such a ship could provide the Army by making power projection platforms.
Given the problems of expanding the fleet, will the Navy ever have enough hulls to routinely spare battle force ships for AFRICOM or SOUTHCOM?
In peacetime, these modularized auxiliary cruisers could be used both for quieter theaters to maintain presence while saving warships for higher threat areas; and in high threat areas to keep warships safer from a surprise attack that opens a war against America.
In war, we could rapidly expand the fleet with modularized auxiliary cruisers plugged into the Navy network until ship building can react to the threat.
Indeed, if we build enough of these mission packages, the cost will decline and we might be able to afford to stockpile them to make the ex-LCS more lethal during war.
