Not really. The hips are essentially unrelated to the slope of the back (that is more of a lower leg angle and height of the withers issue). The exaggerated slope you are talking about is more prevalent in the American AKC GSD bloodlines, rather than in the German lines of the GSD. They are essentially a separate breed now. (I work with German lines exclusively, not with AKC lines.) You are starting to see this sort of structure in the German lines now, but not as exaggerated and extreme. It is essentially a fashion thing...
Hip dysplasia runs about 18% in the breed right now, and is about a low as it can go, due to genetics. Don’t know what the rate for Malinois is. I tried to google it, but got nothing useful. I would expect the rates to be similar or even higher for them, as GSDs have been screened for hip and elbow problems a lot longer than other breeds.
Malinois are more athletic dogs, geenrally speaking, as they are built smaller, and are more refined in bone and strength. So, generally, they are smaller, quicker and faster than most GSDs. But, like all generalities, it only applies so far... I have had several female GSDs that were somewhat smaller than most, and they were as agile as a Malinois, and more resilent and physically stronger, due to their more robust structure.
Interesting. Thanks for the detailed reply. I’ve always admired GSDs, but personally I’ve always been more of a scruffy terrier guy.