I think the problem with Prada "girls" right now is Miuccia (and the people who work with her) cast too many people and don't really focus on them: one model opens S/S 09 show (Ymre) and then she gets the campaign, another one closes it (Sigrid) and she also becomes part of that campaign, which at the same time is starred by other six models. Next season only Ymre and Anna are cast for F/W 09 campaign (what an awful campaign, by the way) with other three models (one of them opened and closed the show, Katlin). Next season neither the model who opens the show (Wixson) nor the one who closes it (Kosushkina) get the campaign, which is starred by a girl who only had an outfit at the show (Rasha). Rasha, despite of getting the campaign last season, is relegated to a second place when she only has a single outfit at F/W10 show, and not to talk about Ymre, who isn't even part of the casting... For F/W 10 a girl opens and closes the show (Samantha) but the campaign has nothing to do with her, and a model who didn't even walk the runway gets it (Daria). Angela didn't walk the runway either but she was a Prada girl a while ago.
It's distracting and definitely it's not the same as focusing on a model for a long while.