I would also suggest considering the placement/flow of the short "Data Model" and "Mental Model" sections. They feel out of place where they are. Are they intended as part of the intro to the topic? If so, I'd suggest placing them higher. Are they intended as part of the use cases? If so, I'd suggest embedding them in that section. After moving them, I'd suggest reviewing their specific text to see if the flow to them can be improved for their new location.
I would also suggest considering the placement/flow of the short "Data Model" and "Mental Model" sections. They feel out of place where they are. Are they intended as part of the intro to the topic? If so, I'd suggest placing them higher. Are they intended as part of the use cases? If so, I'd suggest embedding them in that section. After moving them, I'd suggest reviewing their specific text to see if the flow to them can be improved for their new location.