Did you try Nebula's suggestion of disabling model damage in order to achieve a more to scale size?
Either way, it looks great ingame.
I just thought, how the hell are you going to get the mothership ingame, seeing as it is huge (15 C.Ds seperate from the underside of the mothership) when compared to the City Destroyers.
That is, if you are planning to do the Mothership of course.