Yeah, you can't really hope for a fleet game and then be upset that it's not in scale the way X-wing is (setting Epic aside). The set of ships is a bit too heterogeneous for that.
I'm not so sure that I agree that the heterogeneity of the ships makes it imperative that it couldn't be done to scale. The scale of Star Wars is part of its allure! The Star Destroyer swallowing up the Tantive in ANH was... one of the major scene-setting moments.
If they can come out with a 12" Tantive for X-Wing, then I think they can come out with a similar-size model for the ISD. Also, they can reduce the size of the corvette-size craft.
(Maybe they could train fleas to wear costumes so as to play the fighters... Okay, so that was not serious, but the previous point is in earnest.)
Armada's Tantive is talking Executor territory. ISD'll probably be noticeably bigger than the Victory but hardly a giant centrepiece.
Edited by Lagomorphia