Sometimes, and no.
Yes its all possible, I've seen people do it. You can't however move right past their noses as far as im aware. but with high enough sneak you can sneak past them pretty well.
Sometimes: Yes it is possible but you better be quick to click sneak skill.No: Right in their line of sight as in they should be able to see you (Like a player) or just if they're looking your direction?
My guard system is this : Where is hex when we are spawning in base i have melee mercs with super sledges about it .
can u sneak around that?
