The panel.order attribute in userInputSpec.xml doesn't make any sense. The documentation says:
This is the order number of the user input panel for which this specification should be used. Counting starts at 0 and increments by 1 for each instance of the user input panel. If a spec should be used for the second occurrence of the user input panel use order="1".
Actually, the order of user input panels are given by the order they are defined within
and addtionally depending on panel conditions they might depend on. That's really sufficient and explicitly assigning an order to the panel definitions is ambigous.