SOLID post, Jla!
The Football metaphor works. Brilliant actually. We create play books at Joe & Co. for clients who wish to start a content marketing practice. Your logic to product development applies to content: not having a plan or the basic architecture in place is disastrous, especially when social media can become volatile overnight.
We design our play books to establish content work flows, engagement protocols, response matrixes, and community management implementation, to name a few.
Kudos for your due diligence and thought-process in this piece.