This Achievement is missable! I have tried the Achievement in the Predatorchallenges but it does not work there. (or i´m to dumb)
So that'll have done it in the main Game. The first good Place is the Ship (Theatre Room), where you looking for the Penguin. That's about 1 hour after the start the Game. The Game has a lot more Places until the End.
You can combine the Achievement with the
If you are in the predator Encounter (Room or Place), use RT to sneak and move in the Room. Go to an Enemy and use behind him the silent takedown (Y Button) then go to the next until the room is cleaned.
In the Spoiler is my Video from the Theatre Room.
Regards