Anglican identity

The bishops of the Church of England are making a long overdue proposal to secure for itself and for the other churches in communion with it a stronger confessional identity: Anglican 'rule book' proposed. At first glance it sounds good, but the old cliché about closing the barn door after the horses have left would seem to have some relevance here. My question is this: Why not simply reaffirm the Thirty-Nine Articles of Religion?