I don't particularly like that metaphor either.
There's a variation of it that is more realistic in my opinion.
There are sheep (= brainless followers, basically everyone who's being controlled, a group which includes the everyday worker, small time criminals, basically everyone who's all the way down in the food chain)
Dogs (= a group that is used to control the sheep, they think they're doing good and probably are as they keep everything together, but they don't realize they're being used by the pigs, ultimately the good guys in this metaphor, mostly people who have a job with the state and politicians)
And the pigs (= the ones on top of the food chain, the people who are actually in charge of everything, may include politicians but mainly big time business owners, weapon's manufacturers, oil concerns, people with lots of money and influence who belong to certain lobbies - note that there are no actual criminals in this group).
The sheep don't give a crap about anything because they don't have a brain of their own. So they let the dogs control them because that way their peaceful life is not disturbed. They like the dogs for that. The dogs think that there's nothing bad going on and keep doing their job never asking 'why?'. That way the pigs use the dogs who are both somewhat gullible and well-intentioned to control the sheep.
If you see it that way the ultimate goal is to either not belong to any of these groups or be a dog in pig's clothing.