Iamblichus, 1500 years ago, explicitly telling us that yes it is possible to reconstruct damaged traditions: "For all these reasons, then, let us call upon the gods as our leaders, entrust both ourselves and our discourse to them, and follow wherever they may lead. We should not be deterred by the fact that this school has long been neglected; that it has been hidden beneath estranged teachings and certain secret symbols; that it has been overshadowed by many false and spurious writings; and that it has been obstructed by many other difficulties of the same kind. The will of the gods is enough for us, and with it one can endure difficulties even more perplexing than these." - Book 1 of On the Pythagorean Life; Literally the first thing he says in the book that he gave his students to read first of all. I highly advise you to save this quote for future use when arguing with those guys who say "but your line of transmission is broken bro, just become a sufi bro"