Really diggin the straight black and white soldier dude, would love to see more of those.
With the guy jumping through the air I reckon if you paint in the background, even roughly it'll help the image develop by giving you colour options to pick out from and help the image appear. It might be a personal thing but I feel the momentum of painting an image can really roll when the image appears as a whole. It just seems like you've zoomed in and paid heaps f attention to the face at theis point even though the rest of the image needs some lovin'.
I think with those enviro pieces there could be some more narrative elements. For example in the first frame rather than have stormclouads already abouve the castle, pehaps have them rolling in from the side so it gives more of an impression of an approaching storm which plays into the idea of "storming" a castle.