Marks of a True Anglican Church

The question isn't so much whether episcopal polity is or isn't valid. The Reformers didn't consider it a deal-breaker when considering what constitutes a true church. In the last half of the 16th century the Church of England had an episcopal church government and was considered a true church by the Continental Reformers. Calvin recognized the Church of Poland, a reformed church with an episcopal polity. I think where things get murky is when episcopal polity is equated with a historical physical succession of bishops and as such a necessary component of the marks of a true church.

John Jewell, a bishop in the Church of England said it up well in one of the Homilies, part of the Anglican confessional standards:

The true Church is an universal congregation or fellowship of God’s faithful and elect people, "built upon the foundation of the Apostles and Prophets, Jesus Christ himself being the head corner stone." [Eph. 2:20] And it hath always three notes or marks, whereby it is known; pure and sound doctrine, the Sacraments ministered according to Christ’s holy institution, and the right use of ecclesiastical discipline. This description of the Church is agreeable both to the Scriptures of God and also to the doctrine of the ancient fathers, so that none may justly find fault therewith.

Now one can argue the meaning of those three marks, but conspicuously missing in Jewell's definition is any necessity of a physical succession of bishops or even an episcopal polity.