Although I think the absolute maximum range of fire should be about 4k.
Been also peeking around the files, using CMP editor and found tons of different turret models. Some looked really nice with 2 or 3 guns on them. Sadly none of them is being used as a player ship-mountable...
WW2 capships always had a mixture of weapons. 2 or 3 heavy turrets, for fighting against heaviest-armored targets at maximum range, Some smaller, mostly 180-150 mm "secondary" turrets against destroyers and other smaller naval targets at medium/close range and lats but not least the smalest, destroyer-grade guns, useable as heavy flak against aircraft or light naval targets as transport ships for example.
And imo, disco could go after this pattern. The limited power supply would prohibit the mounting of all-primaries, but be too much at the same time to be wasted on tetriareis only.