Against Raz's SCA argument for hard positivism

I think Leiter and Greenberg are quite right with their "partial exclusion" critique of Raz's argument that soft positivism is incompatible with the law's necessary claim to authority. I'm not sure their example is quite what they are looking for, though. With a slight modification, it could be immunized against Michael Steven Green's objection:

An official lays down a legal directive: "In instances of this sort, do X; do not consider C ... J." Moreover, the criteria for legal validity in this system include, 1, that directives be issued by this particular official, and 2, that they be consistent with reasons A and B, which are presumably dependent (moral) reasons applicable to a very wide variety of situations.

This is clearly a directive that could be authoritative: we can easily imagine (expertise, democratic respect, whatever) the official's directive being a reason to do X and to exclude C-J from our deliberations about whether to do X. It has served us, despite requiring us to consult A and B to test its legal validity.

This is positivist, because the fact that A and B rather than C and D are among our criteria for legal validity is a consequence of the social practice that we happen to have; it is soft positivist because, as John Gardner puts it in his comment, the A and B reasons do the validating independent of the official's assertion, should he make one, that A and B are in fact satisfied.

Ta-da! Soft positivism. Has this argument not been made in print before? The 1989 S. Calif. Law Review symposium on Raz had a few pieces that came close to this argument (I'm thinking of Stephen Perry's, I believe).