I'm just thinking about some new characters such as journalists, intelligence agents or civilian medics such as International Red Cross medics, with new missions, campaigns, and of course new gears.
I think these new characters are as essentials in a real conflict as soldiers or commanders, and it may be a good way to make new kind of missions, such as report news and pictures from the front line, collect essential intelligence informations behind enemy lines, or help and protect civilian population in war situation.