I like the staging of the figures for this piece. I would keep the figure count to a odd number. Helps to balance out the piece.
I would stick to Gray scale values for a study like this. Color is a whole other study. The brush strokes in this piece are too muddy. I can't make the face out for anything. Allow your viewer to understand your Idea clearly.
Dont' create elements that distract - your Idea should be the only thing we should be concerned about
Use Gestures to really get your composition down before you start to render.
If the Gestures work then the rest of the composition will start to work.