Initially, we contacted European Union customers, in all 3 groups (Willow & Sommer, Willow only, Sommer only), as those orders needed to leave quickly due to changes in EU VAT rules.
Subsequently, we are contacting the Willow & Sommer group so that they can buy one of each doll and checkout. This leaves all those 'Willow only' and 'Sommer only' dolls safe for those 2 groups.
If we had contacted everyone at once, the groups would all have been mixed up as people changed their minds, or bought additional dolls.