Hi Nick,
I like the idea of the 'Yanks' going by road and the 'Brits' by foot. The last figure of the British infantry patrol looks out of place , you might be better to loose him or move him onto the grass on the other side.
The truck looks a bit empty of stores and equipment, so you could add interest there. It might be the flash but the canvas cover on the truck looks very clean. I'd also add a bit of dust and litter to the road, again looks very clean and a bit stark as a result.
This is a neat idea, try moving things around a bit, to try some alternative positions for the troops on the ground and the signage. It's a small area to work in and telegraph poles or road markings might help add interest to the scene. More mud at the edge of the grass verge would also be appropriate, and add a little variety of colour to it.
Hope this helps a bit, just some thoughts.
Thanks for sharing .
Al