I'm currently going through the Glenumbra Thieves Guild questline, and I'm enjoying it in general, but without spoiling anything, disguises are utilized sometimes in order to avoid threats. However, as you move closer to enemies you receive a DANGER notification and an eye icon appears above them to indicate that they might reveal you as an impostor if you move too close to them. My question is, if moving closer to enemies will initiate combat with them anyway, and stealth is generally more effective in avoiding notice, what's the point of using a disguise in the first place? Even if the disguise lowers the detection radius somewhat, it's not perceivable to me to any great extent. Walking past enemies still initiates combat, you lose the disguise altogether, and you have to go find another one, only to have the same thing happen yet again. It just seems like a futile enterprise, especially when I can just sneak past. Am I missing something?
I get that this is supposed to be a stealth mechanic, but when crouching is by far more effective, why bother? I'm not seeing a hard requirement for using them to make progress. It would make more sense if that were the case, I think.