Take one BIG ship. I'm talking BIG. Add more cargo than a dread has and a lot less weapons. Like normal wimpy turrets, and 1 or 2 big a$$ mutha turret.
Make the rheinland one looking a bit like a domed-shaped box, the Liberty one looking like a fat freighter ship - cargo containers on top and all, the Kusari one look like some kind of ancient weapon.
Make the box slow to turn, almost static, yet make it fast to engage hyperdrive - to help traders move fast.
Add 2 capital ship thrusters - to be able to zoom forward fast.
No mines, no torpedo, no forward firing weapons BUT add wasp. this way pirates will think about buying this fat lady.
Set price range between average gunship and average destroyer type.
Balance weapons. The wimpy turrets will be good for hurting player fighters or farming navy/police pilots if you are a pirate.
Just park near pirate base and shoot.
If some heavy ship pops out, just whip out the "holy mother of mercy" gun and deal some indiscriminate pain.
Why buy it?
As a Trader:
-next step from large train. same cargo but better options at hurting people on your way.
-faster to engage hyper drive. thrusters.countermeasures.
As a pirate -
-Larger storage than a gunboat/fighter. This way you can camp longer or take down more transports, or if you feel like it, gunboats.
-cruise disruptor
-then you can zoom fast to Crete/Malta whatever, unload and return at your favorite camping place.
A gunoat forward gun reform would be more in place imo...
Or creating monitor ships (rowboats with a battleship turret)
In combat as it is on this mod, either one of these ideas would be bound for failure. Not agile enough to get away from the capships, not armored enough to stand fighters' fire.