I think swapping in unhelmetted heads that look like normal non-evil humans could go a small way towards changing the context of the miniatures. Like Bewyr said, it's tough to shift these away from obvious Space Nazi, Neo-Sov, Not-Galactic Empire or Not-Helghast themes because of the coalscuttle helmet.
If I had infinite funds I'd pick up a box of these and some standard bare or beret-wearing heads and have a crack at making these look as good-guy as possible.