Is it?
That it was effectively the "second prototype" (though not necessarily the second hull) seems obvious, and it's certainly at the older end of the Excelsior build timeline.
IIRC they used the same bridge set for the E-A & Excelsior in Undiscovered Country and for the E-B in Generations?
The set is modified, but basically the same.
There's no evidence that the Enterprise-B was the second Excelsior off the line, or even the first of that sub-type.
There's a
USS Challenger NCC-2032 on a graphic in TUC and GEN, and in the latter the silhouette of the Ent-B is used, suggesting the Challenger came first. The GEN graphic also shows an unnamed
NCC-2004 as the same type of ship.
The slight wrinkle is that the TUC graphic appears on the Bozeman, which suggests Excelsiors were active in 2278. All things considered, it would have been much better if that ship had come from 2287 instead!
But that does leave open the possibility that the Ent-B type is actually the *original* Excelsior-class (or even Ingram-class?), which was then modified into the NX-2000 configuration for the transwarp experiments (discard the bulky impulse and secondary hull protrusions for more efficient high-warp flight), and then refined again as the NCC-2000 type which became the standard 24th century Excelsior.
And for some bonus compete speculation, perhaps the Ent-B was actually one of the last of those original hulls? The Ent-B on the wall in TNG was a standard Excelsior configuration, so maybe she later got those refinements too?
The Lakota could have been a mothballed ship that was reactivated and recommissioned some time in the 24th century, possibly during the Cardassians or Tsenkethi wars? The registry number would roughly line up.
For even more fun, Leyton might have had some personal connection, handpicking his old ride (after the Okinawa?) for the upgrade programme, using the additional impulse reactors to power the new weapons.
