Maybe there's a reason Andras was worshiped as a goddess and Marchosias has been worshiped as a god. Maybe it's not merely a matter of coincidence or confusion that they both seem to have so many forms: male, female, animal, human, angel, demon, and frequently even mixtures of their own design!
Could both of these Demons by creatures of chaos? Perhaps they are both mercurial and chimerical entities who revel in defying descriptions and conventions, beings who refuse to be restricted by labels or stereotypes in terms of both themselves and their relationship to one another, people who enjoy being whoever or whatever they wish to be, as the mood may strike them, and see it as their personal prerogative to change whenever they see fit?