possible idea for you all to use: scifi ship fleet that develop their own internal culture
maybe they’re not able to communicate well with the planetary internets while in transit, so most fleets are self sufficient for most issues and problems that might occur. As a result these fleets get REALLY BIG over time. So what do you get with self sufficient communities and little outside communication, new galactic society.
Differences could go from slight language slang to an entirely independent ship structure for each fleet, with some shipyards specializing in these making custom crafts for all the fleets in the sector, with these shipyard worlds building off of the fleet culture in different ways, maybe it’s how the system gains power, if all the fleets moving things around come to them specifically they make themselves pretty important to the galactic economy even if that’s all they do.
i’d say the shipyard-fleet dynamic has each custom ship being paid in trade goods rather than money, for obvious reasons this would be easier and more efficient for everyone involved but i could be wrong.
if you have any ideas on this feel free to share them here or something.