I think what bubba is seeing in the croup is an ill-set tail. Because a horse's spine and tailbone are directly connected, often if the spine slopes more than normal, it's tail will be lowset and will create an overly sloped croup. He also appears to have a very slightly roached back, which can also throw off that croup. Otherwise though, he's lovely! Beautiful color...I love the dorsal stripe. He definitely seems 'top heavy' since his front is quite a bit thicker than his hind, but some more muscling in those hindquarters could help offset that. How old is he?