It doesn't exactly explain. RT handles crew and the ship as separate stats. The existent rules state that it works as a regular macrobattery, but on hitting a ship without shields, even if armor prevented it from actually damaging the ship, the ship looses one point of crew. If shields are up, it hits as normal for a MB.
Thier melee weapons are the same. They kill you and keep your stuff undamaged. Sort of fits in with them being shifty traders and pirates.
However, using the description in the book, thier ships almost sound like ork roks or mini space hulks linked together like nicassar dhows. They're basically described as being able to cram an engine into just about anything remotely spaceworthy and then upgrade it with their own, or better, someone else's, technology and then tie it all together into huge space going caravans. From what they're saying here, a entirely Stryxis fleet would include things like roks and space hulks.
One interesting thing is that they seem to have twice as many shields as is usual for a given class of ship. Though it would make sense, given that it's the only surefire protection from their weapons...