I dunno, I've cranked up the speed on an ISD when I was at risk of a CR-90 getting in my rear arc and left it in the dust while I drove off. The MC80 will have less of a chance to escape, but the ISD can book it if it has to and the commander is awake to being flanked. Just as long as that ISD has a chance to escape somewhere.
The MC30 is an odd duck. I'm reading a few local reports about how fragile they are and apart from the Foresight special combo, the only thing I can think of is to never take them without Mon Mothma. As it's been pointed out, the MC30's most effective range is also the most lethal to the ship. Anywhere other than a target ship's vulnerable arc is the most dangerous for the MC30.