That is not really an accurate way to determine who has an advantage in a particular MU, it's highly subjective.
Perhaps I'm unclear on this, but isn't edge-guarding preventing your opponent from returning to the ledge? Either way Bowser's recovery is better than Ganon's, he can cover horizontal distance faster, and has an easier time thwarting edge-guard attempts. Ganon can make it back from farther away, but that doesn't mean much when has very few options to actually get back to a neutral position on the stage.