jdef, I guess I did express a hierarchy: the passage of time. By doing the subject selection first I didn't really imply that it has the top-rank in hierarchy, just that it must be done first.
I suppose that if I did the first step thinking deeply on the 'chain of interpretation' that inevitably follows and seeing it through to choosing the wall on which the final print will hang, then I'd be prioritizing the steps. But I don't, really. At the moment I do each step as best I can, with little thought of where each step 'ranks' with the others.
Maybe when I'm a more accomplished and surer photographer that will come. I'll deal with the philosophy of it then.