Sound and well-accepted are very different things - in the area of parenting, appealing to the authority of experts is really asking to be wrong. That said, I do have a bunch of kids, and in my personal limited experience, the particular advice in the article is sound, as far as it goes. If you have enough energy, there's almost always a way to defuse the situation. Real parents with a few kids and too little sleep do not always have enough energy or time to defuse the situation. Given what I see nursery school teachers do every day, I'd be pretty surprised if the experts can't get good results in a clinic, but that doesn't necessarily carry over to home.