Yo, excelent studies man, those anatomy notes are so detailed it's almost like they were done by a doctor xD.
I love reading all these though, it's also good reminders to oneself on how the whole thing works. I remember just knowing how arm muscles are divided in flexors and extensors helped understand how they behave work and why they are the way they are. So if a character is flexing, some muscles bulge up, if they are pushing, other muscles bulge and so on.
I wholeheartedly agree, I was thinking something similar as I worked my way through this, and hope there's not more of it in the upcoming exercices. That said, it DOES help understand shadow's behaivor in relation to light sources, how they stretch, fade and their position in relation to the light. I can see why these where included even if I'm not a fan of it.
And those sketches from references look awesome! I couldn't help notice Cammy grew a bit thicker on the thigh, though you did mention you did some "Adjustments to fit your tastest" xD.
But for real, your line work is amazing, I look forward to your works because they rock and also so I can take some pointers.