They began by equalizing all things . . . . They knew that each thing had something acceptable and something unacceptable about it and declared, 'To make a choice is to lose the all-pervading; when one thing is taught, something else is blocked out. But the Dao excludes nothing."
(Zhuangzi 33; Ziporyn)
This quote and its interpretation so closely resemble Zhuangzi's arguments that one can only wonder at who inspired whom. As stated in an introductory post, Shenzi was Zhuangzi's older contemporary and Hansen, at least, sees his writing as having preceded that of Zhuangzi. In any event, upon consideration, what becomes most striking here are not the similarities between their positions, but their differences.
First, there is the application. Shenzi (if we can believe the author) sees his equalization of all things as a call to cease making choices altogether; to make a choice is to acknowledge differences and Dao recognizes no differences, ergo, make no choices. This position is extreme, and I think we can understand how this is so if we look at it within the context of the paradoxical nature of the One and the many. The tendency, should one be inclined toward a vision of Oneness, is to believe this somehow negates the absolute integrity, the reality, of things in their individuation. If there is One, then the many are in some way illusory. Shenzi fails to abide in paradox, but rather takes his equalization of things as literal, as the nature of a metaphysical Reality called Dao.
Zhuangzi would have had none of this. "Seen from the point of view of their differences [the many things are absolutely unique and discrete]; seen from the point of view of their sameness, all things are one." These are perspectives, not metaphysical assertions. Zhuangzi's equalization of things is perspectival. He recommends this perspective of oneness as a way of achieving inner freedom, not as a way of complying with the nature of ultimate Reality. Never does Zhuangzi prejudice the many, things in their wonderful differences, in the name of the One. If the One and the many are logically mutually-exclusive, then logic be damned.
Zhuangzi's position thus enables a subtlety of application that Shenzi's cannot. Shenzi says, Do nothing; Zhuangzi says, Practice wuwei (not-doing doing). Shenzi says, Make no choices; Zhuangzi says, Make choices while informed of the inconsequentiality of their ultimate outcomes. Shenzi says, Learn nothing; Zhuangzi says, Learn everything without attaching to anything as if known. Zhuangzi's Dao is "ironic", self-negating; Shenzi's Dao is literal, fixed and absolute. I fear I have done a poor job of articulating (and understanding) how incredibly different these two approaches are and how important. Zhuangzi's "ironic Dao" (Ziporyn's term), is an assumed Dao, not an actual entity Dao, and thus its application is not prescriptively linear, but always paradoxical, open-ended and tentative. Wuwei cannot be practiced without things (events), for it is the things which elicit the responses of following along. We say Yes to the One only in that we say Yes to the many.
You can check out Scott's writings on Zhuangzi here.