can the 2 Pz unit be considered "supplied"? Looking in the play book, it would seem like it but from my understanding of the above rule, only one blown bridge can be passed over. Since the 2 Pz is not adjacent to the blown bridge on the Our R., I thought it was un-supplied.
From the way you describe it, I agree that 2 Pz is not supplied. Which part of the play book makes you doubt that?
(If it's the bit in gray at the top of p. 19 which talks about "counting on the 18th VG to successfully clear Trois Ponts," note that if Trois Ponts had been cleared, supply could be traced from there through Malmedy, rather than across the blown bridge into Vielsalm.)