At the moment, stealth relies exclusively on avoiding cones of visions from the enemy. It's already interesting but too easy to cheese. Some creatures have different kind of detections, some animals can hear you or smell you before they even see you.
I find it silly as well you can stealth right behind an enemy in full plate armor without even triggering a detection check personally.
So there should be another kind of detection for certain enemies. Worgs, bears or gnolls, for example, should rather have a 360 circle around them and if they detect you they would come to investigate around the area you are, just like it's done in mimimi studio games.
It would add another dimension to stealth and would be more challenging in some areas.
