Terry, I am thinking that the shoulder blade doesn't drop anywhere, unless you are meaning the whole body drops, putting the shoulder blade on line with the position you were aiming at.
The shoulder blade is forward and high and unless you are shooting from above and quartering toward, probably should not be impacted by your hit. If it was gonna be in a kill area it should be rearward of the shoulder blade.
As stated in the past, I wonder if most people are aiming behind the elbow and stating that they are aiming behind the shoulder. This certainly corresponds with what I am shown repeatedly during Hunter Ed classes.
From what I have seen in the past (experience) if you hit very far behind the elbow, you will likely miss lungs entirely.
Aiming above the elbow gives you a great clear path thru both lungs and the top of the heart, however if you hit a bit low, you encounter the leg bones which can stop a broadhead. Also, if the deer jumps the string, it can drop down to the point where you hit too high.
Unless you are using a rifle, or shooting at a frozen deer, there is no perfect placement, due to all kinds of factors, most of which are outside our control. "Do the best you can" is all we can do.
ChuckC