Ok personally I must confess (but my feelings aren’t super strong about this) the idea that the Dwarves awoke along a specific longitude doesn’t give me any special kind of thrill... I wouldn’t fight using it but I don’t see the reason for the two dwarven peoples to move from their place of origin. The idea creates the necessity to invent ad hoc theories when we instead could just assume that they awoke where they are, which is a good place and a place where Aulë could have put them.