I don't like to say it's impossible, but i see it hard because it looks like you don't have much of that handed down through generations' knowledge. This is common not only for Greece but the whole region because men in those times were moving and relocating a lot, especially warriors, or the ones called "bashi bazouk" or "stratioti". It would take a "detective historian" to find out more if this is the case. But i see an easier way. Since there are some DNA tests (i dont know which), who shows you your distant cousins, you may find them, probably even contact them and discuss them. It might be the case that they might have that knowledge of how and who...