I don't know. This doesn't detect ranged sneak attacks. Nor players with high mobility who can run in and out of the range, or those willing to switch between spell and sword attacks.
If players can duck in and out of this small circle, they will, and if you say they can't, then what's the point, the AI will detect 100% of the time.
To keep stealth a powerful tool for getting out of combat, without trivializing content, I think it just needs a cooldown. When you break stealth, opponents get a round or two of attacks, before re-stealthing.
No. No cooldown.
The way I see it, sneaking should be an "aggro" mechanic. If you want to keep attention off of one party member and shift it onto another, you should be able to do that with sneaking.
The only time when sneaking becomes cheesy is when you're able to sneak an entire party, so that no one is taking the damage and the enemies just act all confused.
That situation is problematic, and that's why there should be some AI behavior to at least attempt to thwart it. But whatever thwarting occurs, it shouldn't be for parties where some characters sneak and some characters don't, because those parties are just shifting aggro in a relatively fair way.
