Not fair! Cargo can sever itself and do whatever the fuck it wants if the QM commands it and the rest of the station can't? TWO THINGS NEEDED: 1. A way of getting resources APART from mining the asteroid (since cargonia controls it) and 2. MORE AUTOLATHES ON THE STATION!
I suppose the engineers could mine unused parts of the station for more metal (plus they start with a bunch), and they can access an autolathe board in tech storage.
The engineers just cut power off to the rest of the station till they get what they want. That or prep N2O floods and such. Atmosia and Engineering don't break away so much when going independant, they just hold people at ransom.
Cargonia can order tonnes of Internals, if needed. Also, vent welding. If Engineeria cuts power, nobody has it. And then Engineeria is invaded by angry Cargonians with riot shotguns.
Medbayans are next to useless, if not for Chemistry, but even then, they are mostly the ACTUAL supply department in a situation like that, with their meds, grenades and human enchancement, either via engineered viruses or Genetics. Generally, Medbaya, Botania and Falconia (Bar+Kitchen) should form a single, merchant nation if they want to have any real leverage.
Libraria and Chapelia are the Switzerland of departments, along with Arrivals, appendices to the main hallway more than anything.
Researchia is quite powerful, but depends on other departments, mostly for chemicals and, if used wastefully, Monkey Cubes. Of course, it has Robotics, which are pretty damn powerful; on the other hand, Medbayan-Cargonian alliance will make short work of all mechs with EMP. There is also Toxins, and a competent Toxin Scientist allied with competent Atmosian can produce a world-shattering KABOOM.
In comparison, Security does not really have a lot of power - yes, they start with weapons and armor, but they are a brute-force faction, with no real productive capabilities or bargaining power, unless they want to pawn their own batons.