Cyprian's words prove nothing of the sort and, in fact, you can't point to anything that proves why he rebuked Stephen in his "none of us should set himself up as bishop of bishops" speech at Carthage in the 3rd c... excepting that most educated Christians understand that it means exactly as it says w/o the need for apologists to read their  Holy Roman "imperialism" back into various source documents (including sacred scripture, unfortunately).

Anyhow, good luck with your "ism's!"