A lot of history books, including but not limited to those dealing with battles, are handy to read with maps (often topographical ones) of the area open if they're not in the book. Back when I listened to audiobooks while commuting, I learned that a lot of history books were a poor match for the format.
It probably depends on how much military minutiae you get into. I've only listened to a few of Duncan's podcasts but I've also enjoyed a lot of (but not all of) Dan Carlin's podcasts. The thing is they mostly aren't about tactical elements of battles or history more generally. (They probably assume some general knowledge of the overall geography which I have.) I've also read books, not just military but ones like Endurance, that it's really useful to be able to look at a map.
