Focusing on the wrong thing. The elephant drill teaches delaying the swing until the thrower is on the swing leg. You can replace the arm swing you see in the drill with whatever swing you want if that allows you to understand the drill better. The arm swing shown in the drill keeps it simple and natural. No pulling, jerking, dragging; just a smooth, natural, simple swing that uses natural forces.
Same as above, and like I said earlier, focus on the point of the drill. Also, PP isn't swinging straight or flat from reachback to release. In the video you linked, watch her throwing shoulder and upper arm from the forward pump to reachback through the swing. Pendulum action. The lower arm brings the disc in, then out, but it is attached at the elbow to the pendulum of the shoulder and upper arm. Also, if you take a straight object like a ruler and hold it up to the screen you will see that the disc moves like on a wave (there have already been diagrams showing the wave motion from the side.)
To illustrate further, it is the same thing with the windmill drill. No one is saying to start with the disc above your head for your regular throw. The purpose is for feeling the down shift, working on timing and position, feeling how natural forces like gravity can be harnessed for easy power instead of trying too hard to generate momentum or strongarming. Focus on the concept the drill is training; don't focus on the windmill action. That's focusing on the wrong thing.
True, you don't need to do anything, but if you want to understand better, you need to do some more homework. Since you point out PP, there's video where she demonstrates a footwork drill; if you were there, would you tell her that's not how she throws, or would you try and figure out why she is demonstrating that drill?