I picked up Battle Leadership, by Captain Adolf Von Schell, to add to my A Rifleman went to War, by Herbert W. McBride from Indiana. World War I is well covered on the small unit fronts. I recommend for real readers "A Soldier of the Great War" you have to get by a hundred and twenty pages before you are ready to enjoy finding out how Italy fought the Great War, which might explain how easy it was for the opportunists to take over after Victory.
World War I was a cold shock to the Imperialist world, the elites weren't big enough, the colonies had to provide tons of cannon fodder, and Steampunk was justified before it was born. Exciting times in warfare, killing lots of people and animals in all the most modern ways, aircraft, armor, far reaching tube artillery, almost unlimited submarines, gas of various toxins (and you wondered why the high leadership stayed so far behind the lines, it wasn't just the radio or telephone). What a wonderful war to only read about.