I had this idea for choosing your soldier's armor yourself. You could have Mannequin stationed in your settlement, that you could add outfits to the same way you do with followers. When you've added an outfit to the Mannequin you would be asked a price to outfit you soldiers with this particular outfit given it's price and how many soldiers needed to be outfitted with it. There could also be a Mannequin for other roles or maybe you could add more than one, so as to randomize between a couple of outfits. This would really personalize your army and might even alleviate the need for faction packs on some cases.