I haven't "googled" but one thing in this entire discussion and it was about the English translation of the Bible.
I looked up some of the information in the ENCYCLOPEDIA to verify what I had suspected or wasn't 100% clear about. Again, you want to re-invent the wheel but you haven't said but one place where you're getting your info from.....a documentary on TV

. We all KNOW that TV is the most accurate form of research.
Do a little research yourself and you'll see that what I'm saying is far more accurate than your documentary on TV.
Greek slaves were far more educated than commoners in the early Roman Empire. They had to know how to read and write as part of their duties because they not only served their masters in the normal way, but they often served as basically a secretary to them as well. Remember, they were the ones that transcribed books and took down info for their masters since most Romans felt that their life stories were part of history to be passed down.