FWIW, the FASA ship wouldn't result in overlap as such, because there was no FASA USS Ambassador
. Rather, the class ship was one USS Ambassador Hardin
, and the rest of the names were also in-jokes camouflaged as the names of politicians or other leading figures.
So far, we have every reason to believe that the class of which the Horatio
was part had a ship named USS Ambassador
as the class ship. Clearly the class isn't named thematically, as the known names are not ones of known ambassadors (Gandhi
might fit with a bit of stretching, but not Horatio
herself unless we postulate a fictional Ambassador Horatio, and Enterprise
would certainly break the pattern). But we could always speculate that "Ambassador
class" is Starfleet shorthand for the class launched by USS Ambassador Nixon
, just like "New Orleans
class" supposedly is shorthand for the class launched by USS City of New Orleans
(yes, I know, just another in-joke in the Encyclopedia
, but so many take it seriously)...
As for the general concept of overlapping classes, the Royal Navy has to struggle with that often enough: it always has a County class, a Town class, a Duke class, a Tribal class and a River class to juggle, and it's sometimes a very close call to get the last member of the previous County class stricken from strength before the next County class is introduced...