Okay. I think I see what is happening. The whole issue get's weirdly skewed by divine command theory, which is so simple it is hard to see the distinction and which implies a very particular formula for a normative theory. Let me outline the position:

I'm not sure that divine command theory implies "a very particular formula for a normative theory". In practice, many divine command theorists pay a lot of attention to things like casuistry (i.e. case-based reasoning) and situational ethics. In other words, they do morality "case by case" or "fable by fable". Surely any such moral theory must contain a lot of non-trivial normative content. It's not at all the case that all arguing happens on the meta-ethical, "God said it" level.