Sure they do have a hierarchy and I would not even doubt all that much that LH has one .... but a ranking is something entirely different: it is inscribing a value to each passenger and then sorting them according to value.

Which is entirely undoable for any airline beyond maybe an LCC and then only for pax who actually collect miles with them.

Any passenger not collecting miles, collecting with another FFP, any spelling mistake, title added etc etc etc would cripple that system.