Jon, I fully agree with everything you wrote except for the last sentence quoted above. I think its a matter of degree, and that it makes no sense to postulate boxes called science (where predictability is the rule), other non scientific boxes like theology, philosophy and imagination. So there are highly complex systems in scientific models, (and yes, I mean the models themselves, not just the reality) which are difficult to allow predictions. I gave some examples in a previous comment. A great deal of biology, but not all of it, fits into this category, as does the vast majority of humanities like history, literature, art. But not all of it. As a musician, you know that the beauty of music can derive partly from contingency but also from some fairly rigourous rules of harmony, dissonance, melodic scales, and so on. I remember learning the laws of harmony (as practiced by JS Bach) as if they were laws of physics (parallel fifths are forbidden comes to mind).
Even your warfare model is a mix of contingency (just think of the weather issue during the Battle of the Ardennes) and some pretty useful and predictive modeling. I would cite Tolstoy’s long treatment of the laws of war in War and Peace, the curriculum of military academies that include a great deal of theoretical principles based on empirical observations (these can get extremely technical, like positioning of naval forces, and use of artillery). Yes, there are always exceptions. Even Tolstoy’s dictum that larger armies defeat smaller ones does not always hold. But the same is true in all of biology, and to a lesser extent in chemistry as well.
My point is mostly semantic. We agree on the nature of science and other fields of study, and we agree on the role of contingency and complexity. My point is simply that its a mistake to label highly contingent, complex, non predictable phenomena (or the models we construct to study them) not “scientific” a priori. In fact treating black boxes as they were science is often the first step to a better understanding of the natural word.