I read this as: if he's outside of the 3-point line and open, it's in his best interest to get as close to the line as possible and take the shot. He'll never i

I read this as: if he's outside of the 3-point line and open, it's in his best interest to get as close to the line as possible and take the shot. He'll never intentionally step just over that line and degrade down to a two pointer. This fact should really reduce the number of shots in the "just over the line" zone. As you go in a bit, I suspect it's much less likely that he would have started open outside the arc. If a three isn't an option he would take the easiest shot available wherever it was, and "easiest" usually means "closer (if open)". And finally, if he's just inside the arc and wide open, he's going to have time to move a step back to try the three. So I think there are few situations where it would make sense to take the shot just inside the arc.