Update on "what" versus "who"

Reading the excellent, "Good to Great" by Jim Collins, one of the 100 best business books of all time. 

As a previous post mentions, I feel the "what" is more important than the "who"; however, Collins talks at length about how the "who" is more important. 

Based on Collins definitions of "what" and "who", I feel the "what" is still more important as Collins talks about "getting the right people on the bus," which to me is a "what" that leads to a "who."

Thoughts?