Get hold of a real fig 12, and ask the designer to substract all the details that is less than 1/2 thick. Keep the dimension and relationship of the white shapes. For example, the shadow and outlines on the rifle are not observable. Anything that is less than 1/2 thick the artist can consolidate them into the shape.
The easy way is for the designer to scan the real fig 12 into an image and import it to illustrator. He can than trace over over the shape and consolidate the details that are not needed. Tell him that the objective is to " maintain the relationship between the positive and negative spaces of the original graphics, keep the shapes of the positive space and consolidate the details". A graphic designer should understand that right the way. It should be a 1 hour work if he is good and he has the image on file already!
The end product does not even have too look like a soldier. To be honest, the figure 12 is just a jumble of white shape over a black negative space from any distance.