, that still doesn't really support your point. I can look at most vehicles, including the 3 you posted, and roughly figure out the decade they came out in. They are clearly products of their time.
When viewing the Shenzhou it does not look like it belongs in the 2250s. The Cage
takes place in 2254, the only ship they really show is the Enterprise, STD starts in 2256 and the first ship we see is the Shenzhou. These two ships look absolutely nothing alike, setting them side by side it is impossible to see them coming out of the same era. However if I recall they did say that Walker class vessels were already a bit out of date and I am willing to accept that, but the nacelle design is wrong for the time period. Rectangular nacelles as far as any Trek has shown us were not a thing until the 2270s at the earliest with the refitting of the Enterprise.
I don't mind the Shenzhou, it is a nice ship, but it most definitely does not fit the time period and there is no way for them to really explain it in the prime timeline lore.
Here is a rough mockup with how the ship would look with period correct nacelles
It wouldn't take much to make the ship match the time period of the 2160s through the 2250s.