Handling diversity in the Old Testament: Tilling's post

It's a bit hard not to respond when the sacred image of B.S. Childs has been profaned, but I'll restrict myself to a counter question, embedded in a few important considerations.

Chris asks us to choose between three options for handling the varied depictions of God in the Old Testament, represented by Brueggemann, Goldingay, and Tomlin. The fact that Dogmatic theologians such as Barth, Diem, or Webster have been left out baffles me somewhat and compromises the selection from the outset. Why should we assume that Old Testament theologians are the ones best equipped for handling diversity in the OT? One of the strengths of Childs - perhaps the strength - is that he was constantly in dialogue with those from the other theological disciplines (this sets him apart from Brueggemann, whose dialogue partners are Derrida, Freud, and Marx, rather than Origen, Augustine, Luther, and Barth). I would have thought that a dogmatician, whose job is to work with the reality itself to which Scripture points, would be far better suited than an OT or NT scholar, whose job is just to work with the fragmentary bits and pieces (and before people say that at least Brueggemann just sticks with the text, check out this quote: Brueggemann's approach is undergirded by a dogmatic presupposition. The question is, what dogma?).

So here's my actual question:

What are the criteria for deciding? What considerations need to be taken into account for negotiating the diversity of the OT? Is staying within the bounds of the OT itself enough, or must we raise our gaze somewhat and place the OT itself within a broader horizon?

We should perhaps bear this statement by Childs in mind:

much of the confusion in the history of Old Testament theology derives from the reluctance to recognize that it is a Christian enterprise (Old Testament Theology, 8).