I don’t get how these ships cycle through letters so fast, yet a thousand years later Voyager is only up to the J. Maybe they’ve cycled through the alphabet multiple times?
We really don't need to cycle through the alphabet at all. I wish they would have left this trend to the Enterprise alone.
USS Defiant NCC 1764
USS Defiant NX/NCC 74205
Not every ship needs to keep the same registry number.