Of the endurance trifecta, maintenance, crew, and fuel, it is generally hardest to reset the ship maintenance, so you generally want that the longest, and I could see an RP of just wanting significantly greater maintenance supplies for any ship that is on its own outside the home system.
As far as ship classification goes, it comes down to what the smallest tonnage/build cost fleet that will be expected to actually fight as distinct from merely scouting or running?
For myself, any fleet element that is expected to fight will have multiple ships in it, that is just how I design things. Nobody goes into the void alone. But if you want to have anything like the Star Trek vibe, you build ships that are generalists, that have the sensors to detect enemy ships and missiles and any ship capable of independent operation has to be able to handle missiles on their own.
A lot of it comes down to RP. Whether someone likes building fleets/squadrons that are efficient, or building ships that meet a certain aesthetic.