Euphemism:
You can research all the "experts" you want. You research the Greek all you want. But there are just a few scriptures from which to construct a model. I am not impressed by "expert" opinion. When "experts" stray from the facts they don't carry any more weight than anyone else who knows the principles of good argumentation.
Kittel's Theological Dictionary of the New Testament suggests that presbyteros was probably the more common term in predominantly Jewish congregations, whereas episkopos was more likely a Hellenistic term.
How does Kittel know that? He doesn't.
It appears Luke throws the words "older men" around quite a bit. This may suggest some idiomatic use of the terms. People of that day,& certainly Jews were quite comfortable with the concept of councils of older men who constituted a kind of court for running villages. But they also knew the difference between a Chief and an "older man".
Allow me to speculate. Confusion over presbyteros and episkopos may be a matter of evoltuion. Early congregations were governed loosely consisting of a few members often made up of a couple large family groups. Those who learned the "way" first had a type of seniority - they were the "older men" in contrast to the newly or recently converted ones. Groups of people automatically organize themselves. It would be natural for these people to look to the "older" members of the group for guidance and direction. The older men would have a lot of influence. As the Congregations grew in members it is reasonable to believe that specialization and differentiation would occur. It is at this point where a distinction needed to be made between serving as a "teacher" and taking care of non-teaching duties.
When Paul wrote Titus to fix things in Crete he was telling him to organize them. Instead of a loose body of older believers running things he would appoint from that body of older men those who were best qualified to assume the role of Overseer. Many areas would have one overseer. That's why they are referred to as "the" overseer in contrast to the plurality of ministerial servants. No doubt there were some who were not good teachers or not capable of handling some material responsibility that were respected for their good judgement who would also be involved in group decisions. If they were practicing the Christian Principle that ONE is their leader whereas they were all brothers there would be a conscious effort to avoid alienating anyone. You would continue to have a seamless web of people involved in decision making.
As the congregations grew you would expect large cities in certain regions to have many congregations each with at least One episkopos. This was certainly true of Philippi which was the Principal City (though not the Capital) of Macedonia. The same was true of Ephesus. It may have been convenient to use the expression "older men" as an idiomatic reference to "leaders" but the only official titles are Overseers & Ministerial servants.
That's my take. I don't have any more evidence than any so called "scholar". At least it harmonizes with the facts that are available in the Bible. One thing you can't prove from the Bible is that there was an official position that people were appointed called "elder".