I think the codenamed guns and nomad weapons are bad enough! You don't need to slap on battleship weapons!
Let's be realistic here! How would a fighter mount ONE cap ship turret, much less 6? It's impossible! Cap ship guns (Gunboats included) should take enormous ammounts of energy to use, but the battleship, destroyer, and gunships can use their class of guns and below without problem. Why? Because the GUNSHIP weapons were made for the GUNSHIP. The DESTROYER or CRUISER weapons were made for the DESTROYER or CRUISER. BATTLESHIP turrets are for BATTLESHIPS only! How would a civilian ship be able to mount even gunship weapons, much less anything else? For that matter, how can ANY ship short of a gunship mount gunship weapons?
Battleships can mount anything. Cruiser/Destroyers can mount anything BUT battleship weapons. Gunships can mount anything BUT cruiser/destroyer and battleship weapons. Anything else can't mount the gunship, cruiser/destroyer, or battleship guns because they can't supply enough power.
*Whew!* Ok, rant-mode off.
This is the real true story of rock and roll; it was not about anything more then, how to live your life, as a gangster, in sartorial splendor, and turning the world into a place where normality would never return again...- Malcolm McLaren