The other thing about the drawn lines for the shoulders is they hollow out the back shoulder line, and it also has ease in it, so it is longer than the front shoulder.
As you ease any straight line in, it develops a hollowness, so ease in combination with a drawn hollow line, makes the shape even more hollowed out. They tend to compensate that with a bowing out of the front shoulder.
One of the things that isn't mentioned is the more ease you try to get in the back shoulder seam the more bowed it should become, because a more prominent blade requires the length.
If for instance you need to sew a dart instead of easing the line in, you will see how that is needed.
There used to be a few excellent pictures on the old C&T site of a German text that showeed correct and incorrect placements of shoulder darts in men's suits.
I think with a true pagoda shoulder you would see a bit more shaping at the end of the shoulder, but i guess it would depend on many things- the shoulder of the person, how much padding you want to have and how extremely obvious you want the final silhouette.