EDIT: MGLT *could* be SW-talk for "delta vee" or "velocity increment". i.e. the change in velocity a rocket gets when it expells its entire fuel load. It isn't a "speed" in the traditional sense of "who will win a race"...but it is a measure of how much the propulsion system can change your orbit. The spacecraft with more delta vee could thrust for longer in combat. That would make it more a measure of endurance or maneuverability than speed. Does that make sense with the MGLT chart?
I think it would be tough to make that work with MGLT/s values. Unless that value is what acceleration can be achieved per second by using max thrust...Up until you reach the max velocity. Unfortunately, that would mean that ships would only be able to use maximum thrust for a very short time.
We could debate this all day, first off we could assume during the Kashyyyk mission that thoses were Victory-class Star Destroyers and they didn't put in a model for them. Also for the one on Raxus Prime, it actually did crash, via falling from the oribital shipyards most likely in the higher atmosphere where some gravitational pull could move it. Plus, I believe that ships could put their sublight drive on in the atmosphere, but it caused a huge ecosystem damage. And Raxus Prime didn't reallly have an ecosystem...(but this could be just for smaller ships and it could of been higher in the atmosphere, since I remember Han once mentioning it and doing that in the Falcon, the spaceport was not happy with him)
We can't really assume those are Victory
-class Star Destroyers, because they're Imperial
-class...If the developers wanted them to be Victory
-class, they would have done that.
I thought I remembered the chick calling Starkiller on the comm and saying that the Star Destroyer was coming after him. Plus, if it was crashing, Starkiller wouldn't have to bring it down, because it would have crashed anyway.
Sure, ships can use sublight drive in-atmosphere. The drives push laterally, however, so they can't maintain altitude unless they can create enough lift to do so, but spaceships aren't designed to create lift, so they'd end up nose-diving.