I believe they are just two different lines of the same morph. Sired from different original animals, being that they had different points of origin they could rightfully be named differently.
Similar to the whole Lesser/Butter thing. The two morphs came from different original animals. Many people may not be able to distinguish a butter from a lesser if they both hatched in the same clutch, as they are generally seen as the same morph. If a person buys a butter then they call it a butter, similarly if a person buys a calico they call it calico;and Vice versa if the animal is bought as a sugar then its a sugar.