I get what you're saying, but maybe this comraderie should be optional? What if I don't want to be identified with my army, what if the army wants to be anonymous? (at the cost of the benefits the paraphernalia brings, of course)
If you don't want to be identified with an army, don't join one.
If you want an "army" to be anonymous, then just use a message group.
Surely the matter of identification of sides is easily solved if all units (or at least bannerless units or untis from bannerless armies) would have the banner of their realm by them (which was already mentioned before?). I suppose you could hide which army you're from, but not which realm? Game mechanics already say that, at least.
I guess I still just don't see why you want to hide what army you're in. I don't see how it grants you any kind of advantage. Furthermore, it is emphatically not the kind of thing that would have been easy to hide, or should be easy to hide: you're moving with these people all the time, you're following the orders of your Marshal in battle—if you don't want to do any of these things, just
don't join an army.
