That would explain why all those figs were there along side the twins when I found them. R4, though. You'd think in a case like that they'd throw a 501st in or something.
It looks like a reader has reported to RS that the "12 pack" is actually just a case/box with 3 of the Twins sets, and an assortment of 6 other ROTS figures, possibly in a stand up retail display box. So it doesn't sound like it actually is a "multi pack" as was earlier suggested/reported.