In fact he goes out of his way to state that there are few sheepdogs, but many, many, many sheep.
Nor does he says that the means to impose [with deadly force] is the obligation to impose. Merely that
a decision must be made. And that decision separates & categorizes who you are.
I've read one or two of his books. I understand what he's saying. The problem is that most people don't read it that way. They read it if you have the ability and opportunity, regardless of anything else, you should respond to something. Since I am not in any situation right now where I have the opportunity or ability to respond, I cannot tell you how I would respond.
Vanya's post was more in line with my beliefs, and did a far better job of explaining it. The idea of being a sheepdog is something that's been romanticized. Some (not all, and not all sheepdog...but this is a consequence of this distinction) people want there to be trouble so they can respond and be the hero.
Personally, I think the categorization of sheepdogs vs wolves is far too simplistic for what is, in reality, a complicated issue. This was one of my biggest problems. You were categorized by your decisions during the fact. But it doesn't take into account if I am acting in the best interests of my family. Would calling 911 instead of drawing and firing on an attacker, who is attacking a third party, in an effort to survive and go home to my family make me a sheepdog? Or a sheep? I look at it like I am making a decision to protect my "flock" even though I'm not acting the way Grossman describes a sheepdog.
It's a very complicated issue that Grossman was trying to oversimplify, and it just doesn't work. And yes, I realize that he even comments on this. But he spends an entire book talking about the extremes of a continuum between sheep and sheepdog, but then puts a little blurb in the last chapter about how most people fall somewhere in between...and he spends so little time speaking about those people.