If there was some sort of damage scaling such that small base= 1 damage, medium = 2, large = 3 it would not only be more realistic, it would mean you wouldn't have the gamey effects of a small base holding up a large base all game.
I consider it already scaled...
I mean, when my ISD runs into a Corvette, that Corvette loses 25% of its Hull due to the impact... My ISD loses less than 10% in comparison...