Given its location, they need an architect group that understands NY. That folks... is SHoP. I'd put my money that if you want a tower that will not only fit in for area, but complement the jewel that is Chrysler, they need to call in the professionals. Not BIG Group, sure as hell not Kaufman or Sam Chang Group, not Vinoly, hell... not even AM Stern... nope... call the SHoP gurus.
When a landmark is needed at Defcon 1, those are the folks one calls.
Its a matter of National Aesthetics Security.