There is no candidate in my opinion that is going to have all boxes checked on what is needed to run a huge company like Disney. There isn't a candidate, neither internal nor external, that has both Parks and Studios experience. So they need to stop looking for a single person, and go with the co-CEO role, where someone from Parks runs the operations side, and someone from Studios runs the entertainment side. Its worked for many companies, and even worked for Disney in the past.
This is where you can utilize both Josh and Dana for their respective experiences in those roles.
So stop looking for a single person, and go with the co-CEOs.