I think the biggest issue with stealth in Arma3 is that there is no feedback on stealth, every time you get detected you haven't got a clue what exactly did or did not tip the AI off.
I did some tests with the new ASP Kir rifle that came with Marksmen DLC and you can kill an AI in a group without getting detected, so it's not impossible. dsylexci's video about the rifle does mention AI responding to sonic cracks, so maybe it's just that every stealth mission uses the wrong weapons for the job.
Then again I was present at the mission that started this discussion and the enemy was likely within 100m of us in a forest (and I put them there to do what they did), in broad daylight and Variable was actually killed by a friendly, so the real discussion we should be having is 'don't shoot crawling guys'.
I did some tests with the new ASP Kir rifle that came with Marksmen DLC and you can kill an AI in a group without getting detected, so it's not impossible. dsylexci's video about the rifle does mention AI responding to sonic cracks, so maybe it's just that every stealth mission uses the wrong weapons for the job.
Then again I was present at the mission that started this discussion and the enemy was likely within 100m of us in a forest (and I put them there to do what they did), in broad daylight and Variable was actually killed by a friendly, so the real discussion we should be having is 'don't shoot crawling guys'.