Time for star wars fan critism
The small troops legs are shorter than they should be. Imperial AT-ST walkers are taller than you've shown in here.
The bomber should probally be a heavy fighter, with the TIE interceptor medium, and the TIE fighter a light fighter. Huge and massive fighters could be larger bombers with more intricate details, such as more weapons, and the interceptor's wings.
And now for some compliments, questions, and suggestions
How about the extra ship is a Dreadnaught Heavy Cruiser?
http://www.starwars.com/databank/sta...ght/index.html
In the Extended Universe, a fleet of 200 Dreadnaughts, fully automated, were found and used to supplement Thrawn's fleet.
Re: Star Wars Imperial Ship Set
Threaded Mode