Where does dual-role occur? Small traders, Scouts, etc.
Anything big enough, they'll have dedicated officers.
I'd think a lot of times, crew on those ships, just like employees of startup companies, would be attracted and held by either a profit sharing percentage or a minute share of a ship. That would allow a lower payment for monthly pay and that would help the cash-flow situation of most small ship captains.
Just a thought.
Also, note that the game is a bit silly in bifurcating roles quite like that.
For instance:
Running a modern comms package on any starship should be fairly straightforward. It's doubtful that you'll even need more than Commo-0 in 95% of cases (other than having to fix a comm system that was blasted by a laser or something).
There's no comms officer on passenger or freight multi-engine jets and that's likely pretty close to what small starships are. On bigger ships (say supertankers, etc in our world), they do have a commo operator. But they often still could be operated by someone with Commo-0 without to much issue.
And really, requirements for anyone to be issued a ticket for their trade should look something like (you can adjust my skill naming as I forget the MgT changes so I'll be descriptive and I've added some missing ones) - and these are absolute minimums in a small ship, you'd want better numbers:
Spacer: Vacc Suit-0, Zero-G-Env-0
Purser: Security-0, Steward-0, First Aid-0, Vacc-Suit-1, Admin-0, Carousing-0 (or some sort of interpersonal training - I call it Socializing)
Supercargo: Cargo Handling-0, Admin-0, Mechanical-0, Vacc Suit-1, Exoskeleton-1 or Robot Ops-1 (nice to have: Trader-0+, Streetwise-0+)
Pilot: Pilot-1 (Pilot-0 is not getting out of the 'learners permit' territory), Navigation-0 (realspace), Sensor Ops-0, Commo-0
Nav: Astronavigation-1 (again, level-0 is learner territory), Navigation-1 (realspace), Sensor Ops-1, Commo-0
Engineer (Drives/Plant): Engineering-0 (again, level-0 is learner territory), Vacc Suit-1, Computer-0, Mechanical-0, Electronics-0, Life Support Systems-0, Admin-0
Engineer (Maintenance): Mechanical-0, Electronics-0, Computer-0, Damage Control-0, Vacc Suit-1, Life Support Sytems-1, Admin-0 (nice to have: Exoskeleton-0 or Robot Ops-0)
Communications Officer: Commo-0, Admin-0, Electronics-0
Scans: Sensor Ops-1, Commo-0, Electronics-0, Computer-0 (nice to have: Remote Ops-0+)
Medic: First Aid-1, Admin-0, Computer-0, Socializing-0 or Psychology-0, Electronics-0, Life Support Systems-1
Tactical: Ships Tactics-1, Sensor Ops-0, Tactics-0, Security-0, First Aid-0, Vacc Suit-1, Less Lethal Weapons-0, Melee-0, some lethal weapon-0, Computer-0, Offensive/Defensive Systems (Gunnery, Screens, etc)-0
Owner: Legal-0, First Aid-0, Admin-0 or Liaison-0, plus ship type specific (Cargo Handling-0, Steward-0, Security-0)
Small Craft Pilot: Vehicle Ops-0, Commo-0, Sensor Ops-0
But probably small ships, esp on the fringes, may get a pass on a missing skill (cribbed enough to fake it through the exam). On larger lines or bigger ships, you'd need higher levels (level 1 for most skills, possibly 2 for key skills on bigger ships). And an Owner with qualifications for a role or roles (such as Navigator and/or Pilot) could fill in for that role and not pay himself.
Pilot must be able to execute comms and sensor duties and navigate in real space.
Navigator has to be able to navigate jumps (for interstellar anyway) and real space and sensors would be required
Admin appears where paperwork in support of a role is a legal requirement
Cargo handling should be a skill in Merchant generation as it is a big part of load movement in the air force and on ships. Steward can cover passenger handling.
Security is a key skill to keep ship, crew and passengers safe.
Everyone ought to pass Spacer qualification.
I award a lot of these levels during initial training (level 0s are cheap). GT's skill packages built more reasonable characters than CT or even MT. MT had more skills, but still missed mandatory minimums.
Besides, maritime regs in the real world require less safety gear, less training, and less formal crew qualifications the smaller the boat. You don't *need* a commo officer on your ship. The pilot can take a 2 week course and get Commo-0 (he should have that if he's allowed to pilot anyway).
In a small ship, a Scout with Astrogation-1, Pilot 1, Navigation-0, Vacc Suit-0, Commo-0, Sensor Ops-0, Legal-0, First-Aid-0, Admin-0 and maybe a few maintenance skills (or J-o-T in their place) and who has facilities to do repairs and maintenance on the ship can get by fine. That only requires 2 skill levels. If you want a Gunnery-0 too, that would be a good idea.
Remember, most level-0 skills should be fast to pickup enough to test for a minimal competency. They also could be embodied in expert systems (software for emergency medical, for the legal and admin stuff, commo procedure, etc.) can go a long way for missing skills too. Pilot, Navigator, Engineer.... those jobs aren't so easily replaced by a tablet with some software.