QmlTableModel has the following API to move rows:

    Q_INVOKABLE void moveRow(int fromRowIndex, int toRowIndex, int rows = 1);
 

QmlTreeModel is missing this API. It could be

Q_INVOKABLE void moveRow(QModelIndex fromParent, int fromRowIndex, QModelIndex toParent, int toRowIndex, int rows = 1); 

We need to check that the [fromIndex..+rows] and [toIndex..+rows] are on completely different branches of the tree or we might end up with circular ownerships.