A couple of things have struck me. The individual elements are good, but they aren't tied together. In the first vignette, the soldiers are in a trench. Soldiers in trenches get dirty. The mg gunner would have been leaning up against the trench wall to fire, but there isn't any dirt on his uniform. Likewise the rest of the soldiers, unless they were prepared to expose themselves from the waist up. In the last vignette, the soldiers are all standing on a red cobblestone road. It would have thrown up a lot of red dust, but there doesn't seem to be any on their boots.