Managing nested sorting

Hi!
I’ve been using Linus approach found here: Vuex best practices for complex objects

Where he suggests an array for easy sorting:

However, I have a scenario where the parent can be sorted as well as its children. Children can also be dragged and dropped into a new parent.
The concept is similar to a Trello board, where both lists and cards can be sorted.

Is the suggestion mentioned by Linus still the best approach?

Thank you!

Any ideas anyone?