you are absolutely right. rule of law beats the hell out of rule of man...the problem is that you have to have just men to enforce the law, and so few of us are just.
To be effective at enforcing the law, one has to be aggressive, and again so few of us are aggressive. You need that intersection of just and aggressive, and both are rare to begin with.
You need the sheepdogs to protect the flock against the wolves. Like you say, sheepdogs are the rarest of them all.