The mystery bags are sometimes in the same groupings, so yes you can be unlucky, buy 3 bags that have the same assortment. The Disney couples i bought had the same assortment of pins in each bag, so it was broken up into 3 different groups w/Rapunzel/Flynn being the 16th random pin that substituted for Duchess/O'malley group. the mystery boxes can sometimes be different pairings, with usually 1-2 pins per box, it's hard to know till we scramble for them. The Disney reveal/conceal couples in the shape of a ring, were all the same conceals when shipped per brick, so when we bought multiples they were all the same, but each store would have a different conceal, hence they got mixed up as they restocked the mystery boxes. Last year the mystery reveal/conceal carousel princesses were the same conceal for each reveal, so some bought certain ones to get more of the conceal (merida). Hope this helps.