I know Diagon Alley is 100 miles away, but for the theme park world, you are going to have to suspend belief and some adjustments are going to have be made.
For example, would Cinderella's Castle be just a few hundred feet from Beast's castle? I also know that Hogwarts isn't that short of a walking distance from Hogsmeade. Some sacrifices have to be made for Theme Parks. C'mon people, stop getting your feathers ruffled over something this petty. Not everything is going to be 100% perfect as far as locales. As long as it's well designed, and can translate into continuing a great story, you'll see it be built.