Savathun or Xivu?!

Ok this makes me mad, why is it that Xivu Arath's hive look the exact same?! Take Megor, Spawn of Xivu for example, they look exactly the same like any of the Savathûn's Hive!? Couldn't they just, change their color or something? They did it with the Grasp of Nokris, it just seems lazy to not do it with the Goddess of Hive warfare. Vergil the Ghost

taken vex, Cabal, and fallen are savathun hive?

This is confusing, how can a taken that isn't hive be a savathun hive?