I use them just as you do. It's nice when the local population is your Ally. Having an area with a Bacta Tank & preferably a few Anti-Vehicle turrets along the way is a must. The biggest problem I had was the Imp Artillery, usually lost 2 out of 6 Infiltrators from suprise blasts. Was a huge problem not knowing where they were before they fired.
Heh, try raiding a planet with Boba Fett as Imp for a huge challenge. I'm suprised how bad his blaster is against infantry. I've managed to kill/dirve off? Han, Chewbacca, and Obi-wan with the right build pad configuration/flame thrower usage. All just to destory a couple of Ion Cannons heh. I wonder if anyone has made a Storm Commando unit.