On the tutorial from atailor you'll notice the fabric is shrunk in with an iron across the front. This can be done from the center crease to the darts on the back part. That's what drawn in is referring to. This remedy is all about sewing techniques that some tailors are comfortable doing this and others don't. If your concern is to have the pockets lie flat you need more room across the fronts. A small dart at the center front would help and distributing fullness over the hips should be done regardless if you use a dart or not. It just makes the trouser fit better and more comfortably. Some tailors don't grasp this like some chefs don't use the same cooking techniques. These are tailored trousers and they should have some ease across the fronts to fit and hang well. Don't fit them too close like jeans.