So now you have 12 ships, like the Enterprise and a number of ships not like the Enterprise, yet still sporting a similar configuration.
This is exactly why both Starship
-class and Constitution
-class both work in regards to the Enterprise.
They started with the twelve Starship
-class vessels in the late-2230's/early-2240's. But as they built more and new technology was integrated, they began using sub-class names to describe the differences between vessels.
The Enterprise starts her life as a Starship
-class vessel and at some point is upgraded to Constitution
- class specifications. Either Pike or Kirk kept the original dedication plaque as a reminder of where the ship came from.
I can buy into that although my alternative thinking was that the Enterprise started off as a Constitution Class and another starship, the USS Starship, got upgraded into it's own subclass and brought the Enterprise and ten other ships over. When the Enterprise got upgraded in TMP, it spawned the Enterprise Class. Starfleet got tired of tracking them by subclasses and brought them all back under the Constitution Class near the end of their service. All future references thus only refer to the Enterprise as Constitution Class. It parallels the USS Boston in real life