Hmm… The muscle tissue of posterior deltoids do not insert to the end of the spine of the scapula. There’s a flat tendon area, like how Eliot Goldfinger describes here. It’s just a round belly of the muscle as the rest of it turn into a tendon:
http://i.imgur.com/gYyQkto.jpg
But yeah, overall nice job there, and I love your The Order 1886 work as well. 