I realy love this. I think you really captured their desperation/resilience. I feel I can realy imagine the soldiers saying:"but captain, we're ridiculously outnumbered!" "Your point?" "What are we going to do...?" "We're going to kill them all."
Don't underestimate how important colour and shading are, they can make or break a picture, and can completely change its mood. I'm happy to say your colouring defiantly falls into the "make" category.