Cool. In seriousness, though, if I were designing a pirate fleet it would revolve around two ideas:
1) High speed
2) High CR decay rate
I don't agree, the ludic path already has this with their safety overrides. Pirates can fly with very large fleets, and their capital, the atlas mkii isn't fast at all. The same thing can be said about the prometheus mkii, but that ship has a burn drive to make up for it. The ludic path is all about hit and run, the pirates are more about raiding and using whatever they can find, which the atlas mkii embodies perfectly. Furthermore, the pirates don't have the nanforges and blueprints to build really high end fast ships. They do if you give them blueprints, but untill then they are stuck with mostly slow low tech and maybe a couple of midline ships.
Other note: Pretty much every civilian class pirate transport should at least be considered for the Salvage Gantry hull mod. The reasons being that it is something pirates need more than anyone else and pirates are improvisors who probably wouldn't want to have to drag dedicated salvage ships around when they could just kitbash salvaging gear onto their cargo haulers instead.
This is something I can agree with. You could make the argument that it doesn't matter, since the pirates aren't programmed to loot the things they destroy, but it would make sense for them as a faction.
Conversely, since pirates aren't into the whole "peaceful expansion" thing none of their ships should get survey equipment.
Ditto.
Finally, and not sure if this is really possible but I'll throw it out there just in case it is: Instead of the Ox Tug, pirates would use something similar as a sensor mask. That is to say, a small ship with similar stats to an Ox Tug (i.e. non-combat, high upkeep) that would actually have an inverse detection radius (i.e. a large negative value, such as -500) that would actually lower the total detection radius of the entire fleet that they're in. Obviously this would be for ambushes or losing pursuit and nothing more.
The ship you suggested is an interesting, but not a very good idea. Put three of them in your fleet, and you could hide 10 capitals (excluding the sensor profile of the ship that provides the bonus).
If you gave them a percentile reductions, like for example 30%, that stack in the same way the salvage gantry's bonus stack, putting four of them in a fleet of 10 onslaughts (again, excluding the sensor profile of the ship that provides the bonus), would make reduce the fleets sensor profile from 1500 to 360, (1500*0,7*0,7*0,7*0,7 = 360,15), which is completly ridiculous, while even a 10% reduction would reduce it down to 984 (1500*0,9*0,9*0,9*0,9 = 934,15), which is just way to low for a fleet like this.
The pirates of course won't put four of them in a fleet, but you can. The argument "don't use them if you don't like them." isn't a good one, because even if I don't use it, the other factions still can, which puts me at a disadvantage I got because I felt like I shouldn't use a mechanic that has a lot of flaws.
500 isn't it, and I really don't know what the upkeep for a ship like this would be, but there is probably a sweet spot for both of them. But then you run into the problem of explaining why only the pirates use it ingame. If it reduces your sensor profile, most likely every faction would want to get their hands on that ship. If everyone start using them, there isn't really a point to them anymore, since everyone will have the same reduction is sensor profile, which just makes it harder for fleets to find eachother. This only favors smugglers, but they already have it easy enough since they have the patience to go dark and fly across an entire system just to deliver 30 harvested organs. And how would a system like that even work? A jamming signal might be an explanation, but don't know how the sensors ingame work. If they work with light, you would have to create a black bubble around you entire fleet to make sure no light reflects back. And wouldn't light sensor get a lot from systems sun, and other stars? If they were radio signals, wouldn't system to system communications be jammed as well?
Some phase ships already have a phase field, which reduces their sensor profile to 0, but apart from one, every phase ship is high tech, which would limit their availability to only a couple of factions, which would give them a clear advantage. You would need to explain how pirates got their hands on them, how the phase field extends to the rest of the fleet, and how the power required could be maintained.
A reduction based on fleet size might work, where smaller fleets get a bigger bonus then large fleets, but then it would result in smugglers and small merchants having an even easier time to get around, which kind of breaks the idea that the sector is a dangerous place for small fleets.
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This became a lot bigger than I thought, whoops...
