I'm thinking they really only have a few J-4 ships.
Tricky, but they've also been around 250 years, so possible.
The 250 years point is meaningless if you can't build an economical starship for the job within the constraints being offered.
Whatever you come up with needs to be "construction rules legal" rather than just a lot of handwavium getting thrown about (pay no attention to the little man behind the curtain!).
The point still stands that it is HARD to make a J4 starship a commercially profitable transport. Not impossible, but it's going to be a struggle (spoiler alert: ticket sales aren't going to be enough on their own). It CAN be done with speculative goods arbitrage, but that option is most lucrative when you've got a variety of trade codes "within reach" of each other, which the Lanth subsector (much like the Aramis subsector)
really doesn't have. Also, Lanth subsector has the lowest population of any subsector in the Spinward Marches, meaning that the commercial opportunities for passengers, cargoes and profit are REALLY constrained.
So not
impossible to achieve, but certainly "easier said than done" in my opinion.
I originally didn't want to use Lanth, since it's at isolated from the rest of the subsector, but it's also the only Class-A starport in the subsector.
The "subsector" is an entirely artificial feature of map making. Broaden the scope a bit more and you've got the following locations for type A starports "around" the Lanth subsector:
- Vilis/Vilis (TL=10)
- Regina/Regina (should be TL=10 in 1105)
- Lanth/Lanth (TL=11)
- Lunion/Lunion (TL=13)
- Paya/Aramis (TL=9)
- Fulacin/Rhylanor (TL=13)
- Risek/Rhylanor (TL=10)
- Rhylanor/Rhylanor (TL=15)
- Fosey/Mora (TL=10)
From that list, it's ironically Regina/Regina and Fulacin/Rhylanor that have the easiest access to the Spinward Main running through the Lanth subsector. Of those 2 options, Regina/Regina is the "most sensible" option for any kind of mining strike on
Dinomn/Lanth (an agricultural world), since Regina/Regina is only 2 parsecs distant (3 parsecs if following the J1 main). Compare that to Lanth/Lanth being 8 parsecs distant and needing J4 to transit from Lanth to Dinomn "direct" across the subsector (rather than needing to take the "long way 'round" with shorter jump ranges).
Just because the company is headquartered on and has its homeport at Lanth/Lanth, it does not follow that all of their ships are built and have their annual maintenance done there.
Are you sure about that ...?
If you insist that maintenance has to be done at the A/B starport of a system with the correct TL, Lanth subsector has D'Ganzio at TL13.
D'Ganzio is TL=13 ... but it has a type B starport, so it can't build starships for private parties.
Good enough for maintenance, but new build construction with jump drives ... not so much.