Star Wars Idea
If people are worried about 'immersion" and the mental conditioning that Stormtroopers are supposed to go through (which wasn't a thing until Force Awakens), maybe go with Naval Officers, even Junior officers. They'd all go through some conditioning (if this conditioning is a fact) but it wouldn't be as 'deep' since they'd have to keep flexibility of thought being officers.
This would also place the characters in a better position to make moral choices, how hard do we have the troopers to lean on people, how strictly do we enforcer Imperial laws, how roughly do we treat dissidents, etc.
[EDIT]
Especially if the characters are the buffer between the higher ranks and the Troopers on the street.
[/EDIT]
This message was last edited by the user at 18:50, Tue 02 Jan 2018.