You guys seem to be very stuck on the whole size issue. I know many before me have said, but the sizing of ships aren't all in scale. It's likely a sliding scale using a complex mathematical formula (similar to the graphic below)
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That is what I was trying to say. If the Corvette was small enough to fit into the landing bay of the Star Destroyer, few would want it, and the dice it throws would look very off. Instead they went with the scale of what looks good, if that is the scale you are using I think that the SSD can be included in the game. Maybe as a Epic or Huge unit I am fine with that, I just want one, and think it would look nice on the table.