I go by their internal name - Secret Service are guards in stealth that wear suits. You can see them on, for example, Train Heist, Firestarter day 2, Big Oil day 2 and so on.

It's mostly for people that do a lot of stealth and wanna try something different to spice things up. If there's demand I may do different versions. Might.

Also, back looks...pretty bad, but there's nothing I can really do about it. It's vanilla game problem (next time you play GGC look at guards there, same thing), that is simply less noticeable when the texture is black.