From my observation, staff eng is a person that has the capability to handle many type of tasks, like what described in the article: Eng, Idea direction, project management, risk management, cross-function communication. Not every eng can grow into this role. Many engs hate politics, talking and meetings. I felt only the large tech organization needs this role. For the small companies, engineer manager who manages less than 4 engs usually do not need a staff eng.