I am very iffy about this book that someone has mentioned to me which is titled Hebrew is Greek by Joseph Yehuda. This book is really hard to find, but the basic idea is that the Hebrew and Arabic languages are descended from the Greek language. I did research on the author, and what little I could find says his research is not accurate. I also heard this is biased to support Greek nationality. Is Hebrew descended from Greek, or is this a farce? J
I am no linguist. I believe the research you have done yourself is sufficient for the question, and I applaud you for your critical thinking and skepticism toward not accepting everything you read. There was interaction between Greek culture and the coast of the Eastern Mediterranean at least as early as 1300 BC. The Philistines are often referred to as "Peoples of the Sea," who most likely were either Greek or had close contact with the Greeks. Tubal may be a reference to a people close related to the Greeks. There was interaction between these people fairly early. I am sure that linguists can tell you how far back one must go to find a common root to the Greek and the Semitic languages. However, Hebrew is considered a Semitic Language, making it more aligned with Phoenician, Sumerian, and Arabic that with Greek. Hebrew is most like Aramaic, not like Greek. So, this theory is probably overblown, as you yourself seem to have concluded. In any case, I do not believe that this theory has much relevance to the biblical texts or their interpretation, so this is an academic question but not primarily a Christian question.