https://www.artstation.com/artwork/Y1JAw
https://www.artstation.com/artwork/mgArv
I think they could have done better on actual release. A few really good and a few pretty bad, but between the rendered characters we currently face and their overtly cartoonish behavior, so much more is left desired.
Art direction.
Civilian/mercenary style is already taken by us the undercover Ghost by default.
Santa Blanca (doh) and Unidad are playing the black and white, hypocritical good and evil theme.
If anything to improvise SB is not about their white color uniform. They need to be more precise and graphic about how dangerous they are when it comes to punishment and murder. Narco Road DLC was supposed to be the even more perfect place to do that. Unfortunately they went with hipster theme instead.
You can notice the UMP-45 in the artwork there. You can also find the UMP-45 in the trophy when you collect all the base game LMG models (funny, since it's an SMG). Leads me to believe it was originally supposed to be in the game. Hopefully we'll see it in the future; having a slower ROF 45 caliber SMG would be welcome.