I think you've reworded it more clearly. thanks.
I don't know the technical word for Matsubayashi's slight 'lean' as you detailed....so I use the word 'lean'. Styles have different sinking methods and therefore different alignments. So you are saying that this 'leaned sinking' is a characteristic of the fighting style of Matsubayashi and not just it's training/teaching strategy towards a common OMA goal? because the 'lean' seems less pronounced and less noticable as you see higher rank.
I purposely didn't mention the concept of 'hara'. I wanted to isolate the principals between side vs back hip power gen. but I agree, 'hara' always leads.