That's a pretty cool idea - hey, perhaps they retired Archer's ship early for the same reason, realizing that every belligerent in the neighborhood had hijacked said vessel sufficiently often or for a sufficient length of time to compromise her military secrets.
I'd argue that Ambassador
is the largest of the Excelsior
family, but not the best solution overall - just like Galaxy
is the largest of her family, but only built in relatively small numbers compared with related smaller designs. Production of the giants would finish when the limited need for them was met, while production of the mediumweights would continue until the far greater need for them would in turn be met. Hence the Excelsior
generation would extend from NCC-2000 to NCC-45000 or so, save for late experiments, while the Galaxy
generation would begin with something like NCC-57000 and run to NCC-72000 - but random factors would dictate that the behemoths of each generation would be built at different relative stages of the generation.
Whether there's a generation between those two, it's difficult to tell. There's some family resemblance between the mid-registry Steamrunner
and the later Sabre
, but all the other designs on that general vein are in the realm of fanfic...