Yeah, in some cases, Yes! but Panos Yiapanis styles for Givenchy (i think) and his style is so opposite to the likes of Gucci, i can't see him working with them, i know Emmanuelle Alt used to style for them until she got made EIC.
I think it's interesting to know, that Panos once styled a Chanel HC show, so he's familiar with these old-luxury houses. And he styled f/w 11 for Roberto Cavalli, whose tackiness isn't far away from Gucci's