Actually, placing the path a certain way and strategically placing buildings, it IS possible to do it. Once again, Uni has some very great minds and creative forces behind them... So yes, we could place Diagon Alley. And authenticity can be stretched a bit guys. It's already the most authentic land, which is what makes it so wonderful. But there are some things you can do... When I explained the whole "no soda allowed in the Wizarding World" thing, she thought it was ridiculous. xD...
As said, they could make it work... A big building (Gringotts anyone?) here, a path change here, a transition of path here (at the end of the path, a floo powder thing that turns you into a shop/the entrance of Hogsmeade? Something along those lines along with a Hogwarts Express walkthrough) and boom, you can't see Hogwarts...