I don't see what's traditional in this plan. It takes an hour to fill, 10 minutes to update. It's not a huge commitment, and you can always change direction, but in the meantime everyone on the team is on the same page.

A lot of founders just don't know how to get started with marketing. Now I can link to this. This a better time investment to fill this out than to read half of the so called marketing advice you can find online.