Anglican doctrine and discipline are based on a three tier standard: Scripture, Reason and Tradition. Is the issue Biblical? Does it make sense? What has the Church said about it in the past? Catholic and Protestant beliefs and practices that meet those criteria are acceptable, while those that do not are unacceptable. This results in a theological system that gives a diverse appearance on the outside (some parishes sing "A Mighty Fortress is Our God" while others sing "Shine Jesus Shine") but maintains a uniformity underneath.
The problem that has arisen is the unwillingness of Western Anglicanism to discipline those who get out of line. My priest has always said that there are canon laws but no canon jails. Unless Anglican leaders put into use an effective disciplinary system, no theological statement will prevent what's happening now from happening again.
Reason, whose reason?, Tradition, whose Tradition?
Anglicanism is now reaping the consequences of its inherent self-contraditions.