[agee]

^ You're right they do like to take the cluster approach. I wonder if it is an Italian thing because even in runway shows, the black models come out one behind the other, I always thought that it reflected some culturally idiosyncratic need for symmetry or order.

ETA:
Perhaps not in recent shows (although I have seen it recently), but it crops up quite a bit in the footage of older shows.

ETA2:
Yep, at Prada SS 2011 Melodie walked followed by Jourdan.