Normal star destroyers are 1.6km long. Home one (rebel flagship at the time) is about 1.4km long. Super star destroyers are 10 MILES LONG. Some of them even packed a death star type laser that was about 20% as powerful. But 20% of blowing up a planet is still probably blowing up a planet. They also had thousands of guns with insane range, and were immune to normal turbolaser and heavy turbolaser fire. The one that was destroyed in the battle of Endor was a huge fluke and very lucky for the republic at the time.
Me and Aarath were joking that we would make one that you would fight where only the tip of the nose would show at the edge of the map and then it would fire a thousand guns and just destroy everything.
But anyway, yeah this game does not really work with such large size differences. It really doesn't work well with the size differences of even the normal star destroyers. Because really if we had a scale where one pixel is a meter, then the SD should be 3x the size it is right now. I'll probably make a "true to source" Star Destroyer vs. Star Cruiser single mission at some point where each ship gets its entire compliment of fighters and everything.
edit:
I've added skipray blastboats, finally found a nebulon B, and added a small fast frigate to the empire side. Going to add another 5 ships or so and then release the next version.