Matthew Williamson

"If you were to caricature us, it would be me throwing pink chiffon in the air all day, and Joseph [Velosa] presiding over piles of money. I'm business-minded. I'm a commercial designer making a product that I want women to pay hard cash for and to wear. And Joseph is incredibly creative. He'll come to me with a business strategy, and I'll go to him with a dress design."

Pierre Mallevays, founder and managing partner of Savigny Partners, a luxury goods advisory and mergers and acquisitions firm in London

"Both are equally important, but I also think it depends on the stage the company is at. Sometimes, a company needs a creative spurt, and other times it needs to get organized under good management. And I do think that, in the case of truly successful brands, behind every successful designer, there is a successful ceo."

On more mature luxury companies, he said, "I think that once the brand DNA is established, then the designer can disappear, as long as the new designer or design team respects the DNA. But the brand has to pass that tipping point for the transition to happen smoothly. Lanvin, for example, is not at that tipping point yet because the brand is still too dependent upon Alber Elbaz and women's wear. That company needs another few years to build success in men's wear and derive the benefits of a symbiotic relationship between designer and ceo, so the jury is still out.

"A designer can be commercially successful, but if there are no checks and balances from the business side, there's the risk they can end up in sublime isolation, geniuses left out in the cold with no real business."

Mallevays pointed to Phoebe Philo and Hedi Slimane as two examples. Both fell out with their business partners: In the case of Philo, she left because she didn't see eye-to-eye with Ralph Toledano, and Slimane made certain demands that his partner, LVMH, was not willing to fulfill. He said the two could now find it more difficult than anticipated to secure a backer because they are essentially working alone — and come with very high expectations of future partnerships. "There is no alter-ego ceo who can temper them."