I have no problem with the E being Constitution-class. I have no problem with the Constitution being the first of the line. Despite MJ's later explanation I think it's what's onscreen that takes primacy. I don't have a problem with the Republic and Constellation being older upgraded ships (mind you never having actually seen the Republic it could actually be another class). I prefer the rest of the 17 series registries being sequential because it's simply more straightforward. Unless there is strong evidence that other ships mentioned onscreen had non 17 series registries that makes the registry really system weird.
I just don't care for Jein's assumption that all the numbers on Stone's wall chart are Constitution-class. It's just too small world for my liking. It's more credible if the chart represents a mix of ship classes.
FROM STARFLEET HEADQUARTERS
TO ALL SECTORS
DO NOT CREATE VESSEL REGISTRY NUMBERS THAT WILL ALLOW FOREIGN POWERS TO EXTRAPOLATE OUR OVERALL FLEET STRENGTH BASED SIMPLY ON OBVIOUS VESSEL NUMBERING.