First, I am no modder. I have learned enough to be a bit dangerous and looked at a bunch of other mods to try and figure things out. Using a program like Blender is beyond my current ability as is scripting. This mod just adds a few things to existing ships. A gun here, a turret there, maybe an extra engine or 2. I wanted to make the pirate ships a bit scarier.

These ships are not available at any shipyard or wharf unless you build one for HAT or SCA. The blue prints are available at HAT and SCA faction reps. I also added most of the engines, shields and turrets (ARG and TEL for HAT and SCA respectively) and generic weapons to HAT and SCA. They will spawn for the SCA as Plunderers, pillagers, marauders, and riot squads.

Version 1.2 update:
Added Minotaur Experimental to the Argon faction. Minotaur Vanguard with a couple of extra engines. Also will appear in argon fleets.
Added an extra engine to the Merlin.
I was dissatisfied with the Drake's combat ability. I added 2 forward facing medium weapon mounts to the front of the ship. I also added a "Drake Main Gun" that can give it some big punch. Only equipable on the Drake and the Cockatrice.
Added two small weapon mounts to the Dissever.
Added ships file and updated the shipgroups file for better integration.

Version 1.1 update:
Fixed the error where one of the Firebird L turrets had no shields.
Yaki ships can mount at least one Mining laser
Added some Xenon gear for sale at the Yaki base (with blueprints)

I would highly recommend the Pirate Life mod by iforgotmysocks if you want to play as a pirate.
https://www.nexusmods.com/x4foundations/mods/377

Small ships were one of opportunity I added what I could, where I could.
Medium Ships got more speed if under 2km/sec and were brought to a level of firepower of a Cobra exchanging 1 forward weapon for 2 turrets, Minotaur excluded.
Large Ships. I addressed what I thought were issues with the original design of the destroyers. The Wyvern just needed to epuip non mining turrets.
Here is a list of ships in the mod:

*NEW* Merlin - Kestrel with some more fire power and now an EXTRA engine.
Adder - Mamba with an extra gun.
Harbinger - Courier Vanguard with more firepower.
Jackdaws - Magpie Vanguard with more engines.
Stinger - Tethys Vanguard engineered for boarding operations.

*NEW* Minotaur Experimental - Argon's prototype Minotaur with a couple of extra engines. Available at the Argon Wharf
Minotaur Raider - Added 2 engines to the ship. More Cargo Space. Escape may not be an option. No firepower added
Auger - Drill Vanguard. I always thought this looked like a space shark with no teeth. I added teeth.
Cockatrice - Osprey Vanguard. 4 more engines. 2 more turrets. Holds 4+1 small ships. Functions as a carrier.
Dissever - Sunder Vanguard made into an anti fighter platform. Added 2 small weapon mounts to the front.
Shag - Cormorant with extra everything. Heavily inspired by the Badger Astral.
Skua - Manorina Vanguard (mineral) extra everything. Very fast.
Jaeger - A Tern with three engines. Pirates will not harass.
Lammergeier - A Vulture with three engines. Pirates will not harass.

Drake - Wyvern (mineral) Can equip L turrets of all kinds. Universal storage.
Firebird - Phoenix Vanguard. Equal in turrets to Rattlesnake plus 3 medium. Almost no blind spots. Can equip different main guns. The turret placement is asymmetric when thinking in left/right and/or up/down. When thought of in 1/3's there is some.
Goliath - Behemoth Vanguard. Made with the idea to prevent a single torpedo from destroying all engines, it adds 2 engines and uses a large shield to protect the inner 3. 6 more Medium turrets for better coverage. Functions as a carrier. Behemoths as carriers are a bit OP.