Smuggler -->> <<-- Imperial Agent.
Trooper -->>> <<-- Bounty Hunter.
imo, i think it's just taken from the movies, plus I mean ..<.< Bounty hunting is Illegal in the republic. they use normal troopers to get people!
as for the empire, yeh sure just replace the BH with a Trooper as well and your done, oh wait that takes away the BH from Star wars, <.< that don't work..yeh you get the point? BH and trooper=the same thing heavy duty class while smuggler and imperial agent is the same.( I played 1 hour of the game at a friends house, cause I don't own the game currently, but I see were bioware ment with all this.)