Kill stealing? Hell, the Infiltrators and Soldiers (or anyone with a high damage sniper rifle) tend to kill much more than I do! More often than not they will kill the enemy I was going to charge to refill my Barrier. Then again, I've never really given a full commitment to Nova so maybe I'm doing something wrong. I tend to charge and let the shotgun do the heavy lifting. Hell, I'll be the first one to tell you not to revive me if I get in a bad situation, usually following up with how it serves me right. The point I'm trying to make is that you can't just put it down to the class, you should look at the Player. If they seem to only be in it for the killing, then they're playing the wrong game, it's about team work and playing to the strengths of your classes.