This is hard to balance of course, but I wish they found a way to make stealth viable and fun while not stupidly cheesy. Also "realistic" in the way nearby characters notice - as I understand, now it can be either "everyone in a large rowdy camp suddenly is aware an ally has been attacked" or "completely oblivious to allies dropping left and right just behind our backs"..
A possible solution is to have only enemies within X meters enter combat on the first round.
Then enemies within X+Y meters enter combat on the second round. Enemies already in combat could shout "we're being attacked!" alerting these other enemies and making it clear that other enemies are joining the fight.
Keep expanding the circle until all enemies in the area have entered combat. This would represent the fact that enemies who are further away take a bit of time to actually realize an ally has been attacked...
This would also help speed up combats: the first few rounds would have significantly fewer enemy turns to wait through.