Creating my own setting [Star Wars flavored]

[Phantasm]

My own (Star Wars inspired) space opera setting has the following (so far):

SM +4: a cargo tug and one cheap starfighter
SM +5: a lot of starfighters
SM +6: a handful of heavy starfighters, several shuttles, and a fast courier
SM +7: a bomber, a light merchantman, and a patrol boat
SM +8: a dropship, an SWACS craft, a racker (carries the SM +5 and +6 starfighters on its hull), several cargo containers, and a tramp freighter
SM +9: a blockade runner, a ship to haul the afore-mentioned cargo containers, and a corvette
SM +10: a cryosleep colonizer ship (appropriately enough called the Botany Bay class), a hospital ship, a passenger liner, a frigate, and an escort carrier
SM +11: a few bulk freighters, a mobile refinery, a scientific research vessel, and a destroyer
SM +12: a hydroponics ship, a factory ship, a marine transport ship, and a strike/assault carrier
SM +13: a luxury passenger liner, and two cruisers
SM +14: a battlecruiser, a battleship, and a heavy carrier.
SM +17: alien imperial command carrier


So the key thing is to determine the role of the ship as well as the size of aliens using them. SM +1 or +2 aliens will need larger ships just to house them.