Have no idea how stealth works in this game, tried to do a Youtube search but there are no videos up on this as far as I can see.
If anyone somehow finds a video on the subject let me know. Thanks in advance.
Stealth works mostly for infiltrator class, they run around invisible and nobody targets them.
For normal soldiers stealth only decides how close you can come to the enemy without making him “alerted” that makes him actively seek and engage your units.
Also this:
l wrote one since you guys must be having a hard time playing this unfinished and unbalanced game
Open up enemies’ info window and check their perception. That is generally 20. Means they can spot 20 tiles away during daylight. Stealth value modifies that. -75% stealth brings that down to 5 tiles. -100% brings it down to 0 tiles, you can bump into them and they won’t even see you. Generally the idea is you go all the way with infiltrator armor or just not care for it.