I like what you did here - there's a lot to admire in the way you chose to pull off this intensely grim close-up on the horror of war.
I'm not sure what I'm going to cheekily refer to as the "musical interlude" was necessary. Frankly there was enough else going on to highlight the brutality and inhumanity of the soldiers and their commander that to me it was a little over the top - gilding the lily, as it were.
Especially considering how powerful the rest of the piece was, I personally found the ending a bit overly pat - again, unnecessarily heavy-handed alongside the rest of the piece. It's not that the ending wasn't poetically powerful, but that you didn't need it to make your point.
There is a lot I really liked about this piece. The descriptive language was powerful and the prose flowed along at just the right pace. I loved how you used animalistic language to describe the humans, and positioned them in the role of raiders and despoilers. To anyone who knows the "traditional" depictions of the Imperial and Beastmen factions, this is a brilliant inversion that gives the work a lot of power.