I have been curing shanks for decades by pointing out two things:
1) When you set up soft for a touch shot with your clubface centered on the ball, with left elbow bent a hair and wrist cocked a tiny bit, the distance from your left shoulder to the clubhead is, let's say, "X" inches. But when you swing, even just a soft swing, THE CLUBHEAD'S WEIGHT AND CENTRIFUGAL REACTION will pull outward from your body, straightening your left arm and unc0cking your left wrist. So at THAT instant, the distance from your left shoulder to the clubface is "X + y" inches. IT GOT TOO LONG for the available distance from your left shoulder to the ball. So your clubhead has to go somewhere (if you didn't lift your sternum): it will either go DOWN into the dirt and hit the ball fat, OR it will move further from your feet and make contact on the hosel.
2) If your backswing is with your arms too low vis-a-vis your left shoulder, and the clubshaft winds around behind your shoulderblade, IT WILL GET THROWN OUT, not DOWN, as the downswing begins. You need to make the backswing plane for short clubs MORE VERTICAL to prevent this. Long clubs have a flatter plane, obviously, so if you are using THAT plane with a PW, you can set yourself up for the shank.
Everything else that causes shanks comes in after 99.98% of the above reasons.
The delivery of a club to a ball ALWAYS is "hosel first" - but you'd have to hold it VERY VERY TIGHT to get it to hit a golf ball with the face wide open...
