The GR-75 Transport was the most heavily featurered capital ship in the battle of Endor, and I really want to see it in Armada. I realize it isn't a gun ship, and it might be difficult to come up with a purpose for it, but thematically it needs to happen.
I expect it might be a good squadron option. A very cheap capital ship that has a moderate squadron value, (1 or 2), and comes with a few titles that allow it to perform a support role for squadrons. Maybe it absorbs damage that would otherwise go to a nearby squadron, maybe it allows all squadrons extra movement value, maybe it even has a way to add extra dice to squadrons..., those these all would need to be in the form of paid upgrades.
How small would they need to be though? Obviously they'd be smaller than a corvette, so would that make it too small for a small base?