"LordDirt;c-2314009" wrote:
Excuse me for my ignorance/forgetfulness but when was Starkiller part of the Empire? I thought I remember killing all kinds of Empire in the game.
Darth Vader kills several high ranking Imperial Officers in Empire Strikes Back. Hell, he ordered half of them to commit to a suicide run going through an asteroid field.
From a world-building perspective, there likely wasn't anything else that could provide a challenge for Starkiller. Empire UFU make perfect sense and continues this trend of "What if?" that CG seem to be pursuing with a non-suit Vader leading Empire units.