Sheep are made not born. If the public are sheep it is because the real wolves at the top have worked to make it so. And that work has been the job of the sheepdogs as well. He doesn't just protect, he is primarily a herder. (Orwell has an interesting take on this in Animal Farm.) The "sheep" don't like the sheepdog not because he reminds them that there are wolves out there but because he resents being herded in an ever tighter circle.
This whole article is infused with the sort of contempt for the public and fascistic militarism that is becoming a disease among law enforcement. Not to mention a Barney Fife-like pretentiousness. You're literally far more likely to die of heart disease from excess dough-nut consumption than on duty, so back it on up a little, Barn. You're not commandos, you're not sheepdogs, this ain't a war, even the criminals aren't war enemies, and you ain't warriors. Officers of the Law is good enough.
"If policemen are sheepdogs, who do they work for? Certainly not the sheep."
Correct - they work for the shephard.
"This whole article is infused with the sort of contempt for the public and fascistic militarism that is becoming a disease among law enforcement." Are you calling the member of the armed forces of the unted states facists? If so, you best be treading mighty lightly........