What I think is so interesting here is that while Walker clearly stumbled backward into this advantage, once he was there he intuitively recognized the benefits in a way that he (and others) couldn’t clearly articulate or defend to others at the time. By the time “Execution” was written, it was a lot easier to communicate this in clear numeric terms and to see it as an obvious path.
Maybe this ties in with with what @joepairman quoted from Good Strategy / Bad Strategy about the “missing theory of strategy creation”