i can see that each major faction in this game uses their own outfit (apart from Lurkers, Lunatics, etc.).
and i remember Gorsky's quest when we have to infiltrate Port Zenith by disguising as one of them (one of the options), the idea behind this is good, where the guards couldn't notice us but kept it hard by not allowing us to get too close as they would blow our cover.
so maybe for short, the disguise doesn't make us completely unnoticeable, only either increasing our [stealth] skill or reducing their field of vision by wearing their outfit.
i think it goes pretty much like this in the flavor text part:
Protectorate Marine Armor (and other Protectorate outfits) > [increase stealth skill against Protectorate soldiers by XX]
Tchortist Robe (and other Tchortist outfit) > [increase stealth skill against Tchortists by XX]
it would take effect by either increasing our stealth, or reducing their effective field of vision while we're wearing it.
and naturally, won't have any effect on other NPCs, or even better, making it harder to sneak past rivaling faction. for example, wearing any Core City faction outfit would make it harder to sneak (or reduce stealth) against the other two factions. this is inspired by Camp Hathor's reaction towards the player if they wear the Rathound Regalia when entering the Camp. but in their case, it's way too hardcore, as the whole camp will immediately hostile. them pipeworkers.
but to make the effect not too dominating, make the stealth skill increased by a small or decent amount, let's say...20 to 30 stealth points or so.
or reduce the corresponding faction NPCs' field of vision by, let's say...a half of their normal FoV distance (if the effective FoV is 20 tiles, then it would become 10 tiles if we wear their outfit). it would help non-stealthy characters by some margin.
it wouldn't have to be exactly like this, but you get the idea.
