Without a third party showing sales of padlock boxes with and without space for two or more locks, there's no actual way of being SURE which is more common. Ev

Without a third party showing sales of padlock boxes with and without space for two or more locks, there's no actual way of being SURE which is more common. Even if there are ten times as many boxes available that only have space for a single lock, what matters in the case of the puzzle is, a box with space for two or more locks is readily available. Suggesting in the puzzle "by the way the box has space for two locks" really kind of destroys the "puzzle" aspect.