Between the initial model and any scalars on the in-game starship entity, the ships are indeed all LFL-approved lore-accurate scale. :)
The main thing that I think keeps throwing everybody off is the FoV on our (pancake) c*ckpit cameras. For the sake of gameplay they are tuned to give players better peripheral awareness, but the down side of that is that things outside your c*ckpit are somewhat compressed. This is particularly noticeable with the width of the flagships and the hangar bays.
Cameras aside, unless we made an export error somewhere that I’m unaware of, everything is exactly as big as it’s supposed to be. Just bear in mind that the movies cheat scale when needed to get the best shots possible, whereas in gameplay our scale is 100% static.