If you've got the time it's worth doing Toverland, it's only a 5-10min detour when going to Efteling from Phantasia. It's a lovely little park, Troy is great and Fenix will be open when you go. Queues were good for the Dutch half term. If you've got the time then Maximus' Blitz Bahn is a cute little ride, just don't do what we did and queue 45mins for it (the queue is tight and stuffy).
As for Phantasia- it's a small in size so there's not a huge amount of walking involved. Queues were never huge due to German efficiency (we visited on a weekend)- the longest we queued was probably 30mins for Taron (however it did apparently hit 2hrs in the morning). They've got a few single rider lines too. There's a lot of shows too so make sure you save time for them. Also to note is the lack of ride photos, I'm not sure if you're overly fussed by them but the vast majority of rides didn't have them.
Efteling is a stunning park as I'm sure you already know! It's decently sized and has a really nice atmosphere. Once again it was the Dutch holidays when we visited, and we probably queued just under an hour for Joris en de Draak! The park has single rider on most big rides. For food I'd recommend Polles Keuken next to Symbolica- they serve really nice pancakes and the theming in there is great (as is the whole park). Live entertainment is also pretty big here, make sure you get to see Ravelijn (you need to get a free ticket for this and see if you can get the translation headsets) and Aquanura.
I've got some spare Efteling and Phantasialand maps if that'd help you plan, if you've got any other questions about these three parks then feel free to send me a message