If you really interested to keep the nodes in a group with your custom order like LIFO(Last In First Out) or FIFO(First In First Out then it’s easy from javafx with the help of javafx keyword insert , into, before.
Nodes on a
Group in FILO(First In Last Out) order. I mean the updated nodes will be at the index  and old one nodes would just swap to index and so on.
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