From the looks of the OP, it seems to specify liners or those civilian ships that specialize in hauling people. Cargo and fuel transports are vital, but crew transports are much more situational.
Mudskipper is okay during the tutorial to haul the people needed to run the free clunker fleet obtained. Starliner is okay as a budget option to haul a bunch of crew to colonize a planet during midgame. Since marines are expensive, I tend to favor Colossus 3s (or Valkyries if I can find them) for ground support package and reduce marines I need to haul. By the time I want thousands of marines to raid a planet, it is endgame and I can use Onslaughts and/or Legions as part personnel carriers (those ships have lots of extra crew capacity for a battleship), part battleships, and dump the Starliners. In theory, Starliners hauling marines could be handy, but that option comes too late when I can afford to haul that many marines.