Feedback please..

So this is a bit of a draft to illustrate the saying "Peace is always better than war", for uni.
In the final of course, there wouldnt be any water marks or writing...And it still needs more tweaking...

Very basic concept explanation is that: Its better to be playing army/war, than be army/war.

So I d like feedback on the colours, shading, composition
( ie: do I need to put something on the wall on the left to balance it?)
What you think in general , any general coments . if you like/dislike etc!

Much apreciated!
oh P.S ~ Digital painting/photomanipulation