The reality is that a Church such as the Anglican Communion is such a mixture of histories, and of theological difference, that inevitably there will be deep differences and from time to time these will lead to grave crises, such as the one faced in recent years.
Like all crises in the church it is complicated. It springs from history, the history of centuries a history of Anglicanism and of the church in England which began before the fall of the Roman Empire and long before Augustine, with Bishops, including at York.