The Mothers of the Apostles

Why is it that most of the Apostles had mothers with Greek names?
We know that Jesus found His followers in the area of Galilee.
The following is taken from the book "The Economy of Salvation" by Helen Tzima Otto. She credits her research to a book by Kharis Skarlakides published in 2005, called "The Forerunners of Jesus Christ: Apollo and the Sibyls."

"Our Lord Jesus began His ministry in the Galilee of the Gentiles, where He retired as soon as He heard of the imprisonment of John the Baptist. At that time, the Gentiles of Galilee were predominantly of Greek origin, considering that the entire region was a few centuries earlier conquered by the armies of Alexander the Great and many Greek settlers came there and remained after the land was taken over by the Romans. As far as the national background of the Apostles of the Lord is concerned, in the beginning of the third cenury of our era, the Bishop of Tyrus Dorotheos prepared their geneology, based on historical information still available at his time."

"It is shown in the Chronicon Paschale, that ten out of the twelve Apostles of Our Lord had mothers whose names were unequivocally Greek."

"Hieroclea the mother of James and John
Sophia, the mother of Philip
Rhea, the mother of Thomas
Ourania, the mother of Bartholomew
Eutychia, the mother of James of Alpheus
Kheirothea, the mother of Matthew
Ammia, the mother of Simon the Canaanite
Selene, the mother of Thadaeus
Joanna, the mother of Peter and Andrew"

"Bishop Dorotheos does not provide any information on the mother names for Simon the Zealot and Judas Iscariot. However, we know from other sources that Judas Iscariot was the only Jew in the group, the rest of them being from Galilee, not Judea, and possibly their fathers belonged to a different tribe (Benjamin, for example)."

I am amazed to know that many of the mothers of the Apostles had Greek names and gave their sons Greek names, eg. Andrew derived from the Greek word for man, Peter, the Greek word for stone or rock and Philip, the Greek for one who likes horses!