Didn't see DD(X), now DDG-1000 in the USMC OOB for naval fire support onwards from 2008...
Anywya, there are some features of the 155mm AGS the team should be aware of for a future v3 implementation:
ERGM is current 5" guns, LRLAP is DD(X)'s shell.
The shell is significantly bigger than any other 155mm shell out there; it weighs as much as a WWII era non-superheavy 8" (203mm) shell and is much more lethal than a conventional 155mm shell.