As I exited Rochas’ stifling show venue, I bumped into two (of my bitchier) friends, who rattled off a flurry of names—Prada, Kenzo, Dries Van Noten—that they thought the collection too closely resembled. And they were right. Marco Zanini’s debut runway show for the French label promoted edgy dowdiness, with ubiquitous cinched waists, wide-shouldered jackets…