Did the Early Church use the episcopal polity?

Churches such as the Catholics, the Eastern and Oriental Orthodox, Methodist and Anglican churches use the episcopal polity, referring to the system which has three offices in the church: bishop, presbyter and deacon. Most Protestants however view the words "bishop" and "presbyter" as synonyms and referring to the same office, either teaching a presbyterian or a congregational polity. 

Here I will make a case from the early Christians showing that they believed the church to have 2 offices.

Jerome 347 - 30 September 420

The presbyter is the same as the bishop, and before parties had been raised up in religion by the provocations of Satan, the churches were governed by the Senate of the presbyters. But as each one sought to appropriate to himself those whom he had baptized, instead of leading them to Christ, it was appointed that one of the presbyters, elected by his colleagues, should be set over all the others, and have chief supervision over the general well-being of the community. . . Without doubt it is the duty of the presbyters to bear in mind that by the discipline of the Church they are subordinated to him who has been given them as their head, but it is fitting that the bishops, on their side, do not forget that if they are set over the presbyters, it is the result of tradition, and not by the fact of a particular institution by the Lord. -Jerome, Commentary on Titus 1:7

Hermas 130-150ad 

 Thou shalt therefore write two little books, and shalt send one to Clement, and one to Grapte. So Clement shall send to the foreign cities, for this is his duty; while Grapte shall instruct the widows and the orphans. But thou shalt read (the book) to this city along with the elders that preside over the Church. 

'"Hear now concerning the stones that go to the building The stones that are squared and white, and that fit together in their joints, these are the apostles and bishops and teachers and deacons, who walked after the holiness of God, and exercised their office of bishop and teacher and deacon in purity and sanctity for the elect of God, some of them already fallen on sleep, and others still living. And because they always agreed with one another, they both had peace among themselves and listened one to another. Therefore their joinings fit together in the building of the tower."

Polycarp 120ad 

Wherefore, it is needful to abstain from all these things, being subject to the presbyters and deacons, as unto God and Christ. The virgins also must walk in a blameless and pure conscience. 

Clement of Rome 1st century

Our apostles also knew, through our Lord Jesus Christ, that there would be strife on account of the office of the episcopate. .... Blessed are those presbyters who, having finished their course before now, have obtained a fruitful and perfect departure [from this world];

And thus preaching through countries and cities, they appointed the first fruits [of their labours], having first proved them by the Spirit, to be bishops and deacons of those who should afterwards believe. Nor was this any new thing, since indeed many ages before it was written concerning bishops and deacons. For thus says the Scripture in a certain place, I will appoint their bishops in righteousness, and their deacons in faith.

Didache 1st century 

Chapter 15. Bishops and Deacons; Christian Reproof Therefore, appoint for yourselves bishops and deacons worthy of the Lord, men meek, and not lovers of money

Ambrosiaster 4th century

For example, Paul calls Timothy, whom he had made a presbyter, a bishop, because at first presbyters and bishops were the same thing... But because succeeding presbyters were not fit to hold the chief offices, the system was changed by judicious foresight,

Commentary on Ephesians