People might say that things like registry numbers are not important, but for me they add to the world building as a whole. In~ 40 years Starfleet only built ~ 300 capitol ships, so yeah they are spread far and few between.
Except we know for a fact that's not how Registry numbers work. The creators have said there's supposed to be multiple methods so adversaries can't accurately guess Starfleet's in-service composition and the composition of particular fleets. IIRC, Maronne also confirmed from his time working on PIC that the idea that large blocs (e.g. chunks of the 10,000s, 20,000s, 40,000s, 80,000s) are set aside for huge production runs is also used behind the scenes, and that registries generally indicate production runs that loosely correlate serially with launch date, but not necessarily. Hence why Galaxy's number would "indicate a 2370s" launch but was contracted in the 2340s and launched in the 2350s. The registries are selected partially strategically.
So TLDR you may be even more correct because the actual number of ships built must be significantly lower than the shown registry numbers.
LD uses the FC uniforms and insignia until 2382.
PIC shows a fusion of the FC/Flashback uniforms in 2381 and switches to the regular flashback uniforms no later than 2382.
PRO uses an AGT-like uniform and insignia for the 2384-2385 period and switches to the PIC flashback uniforms in 2385 and reverts back to the rectangular Startleet insignia.
The LD/PIC contradiction is minor, but the PRO uniforms/insignia stick out like a sore thumb.
Remember the TNG and DS9/VOY uniforms were in use concurrently.
In the real world uniforms often do change quickly, and there is overlap because it takes time to produce and issue them (I understand the existence of replicators throws a wrench in that theory).
Since Parliament-class and Douglas Station uniforms were the same as California-class, I'd hesitantly suggest that it's a "2nd line" uniform. The Parliament-class is a mega-engineering ship (I like W359 project's hypothesis that it was originally designed to build Starbases for the 20-year missions of Project Galaxy), Douglas Stations seems to largely be an operations and logistics hub, and the California-class is largely an operations and logistics ship.
This would fit nicely with the Galaxy-class retaining its "TNG" uniform (albeit we do see them switch to the DS9 uniform in Generations) as unique to that ship.
The Prodigy Uniform can easily be explained as something used on prototype ships. Like the "Racer" uniform for the Delta Flyer. BTW the Protostar uniform is based on PIC's S1 uniform crossed with TNG, and the uniforms seen later in the show could be argued to be a stylistic variation of the LD uniform.