From a streamer I saw attempting Permadeath on Grounded difficulty, the strategy seems to be more consistent. It goes like this... Part 1: After Joel stealth kills the clicker, instead of stealth killing the stationary runner by the see-through window, go and stealth kill the moving runner, then go back and stealth kill the stationary runner by the see-through window. Part 2: Pay attention to the runner, and as soon as the runner moves from the bookshelf, go to the other side by the see-through window; pay attention to the other runner, and as soon as the other runner goes off-screen, wait for 6 seconds, then throw a bottle at the spot (the wall where the door used to be) where the runner was stealth killed to have the clicker hear the sound so it can be stealth killed. Part 3: Pick up another bottle, smash the snack vending machine to have the runner hear the sound so it can be stealth killed; be prepared to throw the bottle just in case. Joel should stealth kill the last runner at that point. It was from a streamer known as AKblackandred on RU-vid.