A Disney vacation with toddlers is never the same as one with older kids. For starters, visiting all four theme parks becomes less important. The first time I did this, I stressed unnecessarily over one simple question: how should I schedule my park days at Disney World?
Quickly, I learned something very important regarding this question, and it is that, when traveling with small children, no park is as important as the Magic Kingdom. My advice to you is that you schedule two days there, even if you only plan on three days of theme parks. After that, it will depend on your kids’ preference. If they like animals, you should choose Animal Kingdom over Disney’s Hollywood Studios. Epcot comes last in the priority list for small kids, because they seem not to like this park as much as the others. It still is a worthwhile experience, but probably better for a longer vacation.
If you are planning to stay around a week or more, it is also important to schedule a rest day for the kids to recover fully. This day could also be good to visit Downtown Disney or the smaller water parks.