Yes, this is a fair point. (There does remain the fact that the dependencies ought to be marked, so that those who lack them can clearly see that they lack a specific, recognized dependency, and so that they may be able to trust that the author will later fill them in, to fulfill the ‘IOU’, as you say. But that aside, I agree that your point does make the case for the “dependencies first” order less clear.)
Yes, this is a fair point. (There does remain the fact that the dependencies ought to be marked, so that those who lack them can clearly see that they lack a specific, recognized dependency, and so that they may be able to trust that the author will later fill them in, to fulfill the ‘IOU’, as you say. But that aside, I agree that your point does make the case for the “dependencies first” order less clear.)