Fortuantely in SWTOR companions don't aggro anything on their own (which makes harvesting materials within the aggro range of a mob ok, as long as you can stand outside it & still be within range of the materials node).
Yeah, if we're going to be "required" to bring companions, we'll need some way to control them, even if it's basic controls such as aggression level (attack anything, attack my target, only attack if attacked first) & maximum distance (short, medium, far).
As with pretty much everything, we could do with more information, and it may not even be finalised yet in this regard...