If I give Bethesda the benefit of the doubt my assumption would be that the 470 has some feature(s) that the 290 lacks that the game can take advantage of resulting in the 470 being better then the 290 in this case, but I honestly don't know enough about the hardware of each of them to say with any certainty. Otherwise Bethesda is BSing us with these requirements and just assumed that since 470 is a larger number then 290 that it must be better.