Well, yes. But, as HZ pointed out, there are only twenty seated officers of every division. That leaves, in the case of 6th Division, 830 unseated, about 617 or 618 of whom know the names of their swords.
The "shikai is not supposed to be that impressive" bit, I'm not so sure on. The only one that's truly unimpressive that I can recall is Ikkaku's, and, to an extent, Rangiku's. Everyone else's shikai that I can recall is pretty impressive, at least when it's used right.