I have to admit, of the four, Karpathy and Sutskever were the two I was most impressed with. I hope he goes on to do something great.
When the next wave of new deep learning innovations sweeps the world, Microsoft eats whats left of them. They make lots of money, but don't have future unless they replace what they lost.
You could say the same about Google - and yet they missed the consequences of their own discovery and got behind instead of being leaders. So you need specific talent to pull this off even if in theory you can hire anybody.