this sounds like a dumb question, but storm is my first gsd. i work at a pet nutrition center/grooming shop and this customer came in with her 2 gsd's today. both were almost 2 years old. they had such sloping rears, and i've seen many like that. storm's rear does not slope like that. is there a reason? is there something wrong if it doesn't slope? is that just a certain line like i've read?