Versus the Armitage, MVAE, Kumari (Does that one count as 1 or 3 ships?) and Defiant retro.
I'd be likely to consider it one ship with multiple loadouts. It's similar to the Universal BOFF load outs that a lot of the KDF ships have, however, there is a very legitimate/fair point that the Kumari [and Odyssey + Vesta] don't quite fit into that mold because of moving a console around as well.
I can definitely see the case for considering it 3 ships, but I personally feel it to be 1 ship [that you buy 3 times! ].