I am a great believer in PH's signature "Bees to nothing invariably". So while supercedure cells are often in the middle of comb and swarm cells often at the edges, and the numbers are often more for swarming, none of these guides are certain.
I would even amend Wedmore's quote "If one of the Queen cells is cut open and found to extend back to the mid-rib, retaining the origional base of a worker cell, one may be sure that is is not a cell built for swarming." Replace "one may be sure" with "one may perhaps be led to believe"!
But in any case, as jimbeekeeper suggests, it would be a brave keeper to be so sure as to leave 'supercedure' cells to develop without doing an AS.
Ray