Re: Constellation Class: Excelsior "back-up" plan?
I would say that Constellation was built for a separate mission parameter with a similar feature in speed, but both class leaders were re-appropriated for testing. It would seem a little wasteful to build two of the largest ships in Starfleet just to test them, i would assume that Starfleet has more access to better simulators then we do. Building different styles of starships in order just to test them feels more like early 20th century rather than mid to late 23rd century.
"As my sweet mother always said, 'son, if one hostage is good, two are better, and three, well, that's just good business!'"