You can see the old school methods of teaching in their mechanics. No sign of internal rotation in those deliveries. Snapping the elbow up on the pitching arm side. Pretty typical of what you see at a lot of youth ball fields across the country. I have a problem with the "T" position reference in that it teaches the student to lock out the windmill arm in that position. No flex in it at all. Or at least that is what the student is going to do if you dont tell them to flex that elbow. Lots of vids similar to it out on YOUtube.