I'd very much like to think that something like this was going on at Starfleet at the time. The idea of the Constellation
piling up old tech to get the same effect as smaller numbers of modern gadgets is a time-honored one - see e.g. the Soviet Kirov
class (Project Orlan) and his conventional backup plan of Slava
class (Project Atlant).
I'd also like to postulate, though, that the Constellation
was marketed as something else, in order to secure construction. Rick Sternbach's backstory is fine with me, as would be the idea that the four-naceller was some sort of a high speed reconnaissance asset (in addition to being a backup plan for the next generation of GP cruisers).
The latter idea would be cool because Starfleet might keep the very existence of such spyships secret for some time - thus they wouldn't be listed in my favorite fan resource, Ships of the Star Fleet
, yet, as this putative in-universe publication is dated at 2291 when certain skeletons would still remain in their closets.