This makes the most sense. Spread it out and get your money's worth. Putting all Nintendo properties in one park just seems a little silly. I'm not the biggest HP fan so I usually just do the rides and get out while making my way through the crowds and try to avoid it at busy times. If one park had both Hogsmeadge and Diagon Alley I feel like I would actively be avoiding a huge chunk of the park for a good part of the day while I try to manage my time to get on more rides.
If someone really didn't care for Nintendo and there's a decent chunk of one park dedicated to it (with HP like crowd too) then yeah....
I just hope this makes sense to other people lol. It makes sense to me anyway
Diversify and put properties in other parks too. Spread it out.