Sorry but why can't a VP of engineering be somebody who should code(even if occasionally) or some who could be competent at a code review. Its precisely this kind of attitude that gives ammunition to the MBA culture of appointing people who are clueless about their current job to manage the best people under them.
The net result is getting people appointed who know nothing about the people they managing, or the line of work. And just take blanket common sense based decision which most of the times are wrong with regards to the domain they lead.
Regardless of who you are- architect, VP or whatever fancy title. If you claim to be the leader of a group of people with some specific skills you should be somebody who at the very least has mastered those skills.
According to me anybody who claims to lead a group must be the best among that group, in the job that group performs.