I actually liked the blank ships in the DS-9 fleets. I read somewhere the idea was that Starfleet was frantically trying to filed as many ships as possible and a lot of those ships were not complete. Some of the Galaxy classes were largely an empty spaceframe with just engines and weapon systems installed, run by a minimal crew instead of complete starships with a crew over a thousand. This makes sense to me- why even bother naming the ships, just have the friend or foe transponders identify them.