For Green Waters, the USN could use the equivalent of a Corvette. Again, there are numerous good foreign designs, but the NIH mindset applies.
The LCS was sold as a glorified, do everything — ASW, mine countermeasures, anti-surface warfare — that was convertible through the use of modules. The LCS was designed for speed at the cost of everything else. [Note to USN: Even at 45 knots, an LCS cannot run from a Mach 0.8 anti-ship missile, nor can it mount an adequate defense against multiples of them.]
Short form: The USN and DoD are screwing the pooch and they cannot see it at all.
One factor likely is that weapon load is compromised for fuel load.
Those things have got to have gawdawful fuel consumption rates.