Intriguing concept. But you could still see halftracks, trucks and light armor in support roles. In German WWII stuff, for example, you'd see Panzer Is and IIs in support functions during a particular timeframe.
But if I read you correctly, this would be more of a figure / diorama kind of build? I wouldn't be able to get started on it any time soon, but it would be cool to do a dio of the scene in Saving Private Ryan (or one like it), in which we see a big office filled with rows of civilian women, steadily punching on old typrewriters, with stacks of paper all around them, and a smaller office up front with 4 or 5 older or disabled Army officers discussing whatever.
Something like that.
What would the badge look like?
~jerry