The lore in Fallout is grossly inconsistent because of a lack of Henry Cavills working at Bethesda.
They have had staff that knew the lore the fact is they decided to change things because it made the game more fun. For example mutants and supermutants should not be in almost any part of the wasteland as the means to create them is not universally available according to lore, yet they are in every single game because they are fun enemies to fight.
Fallout chose fun gameplay over consistency.