Source of Jesus being a relatively common name
Many people shared the name. Christ's given name, commonly Romanized as Yeshua, was quite common in first-century Galilee. (Jesus comes from the transliteration of Yeshua into Greek and then English.) Archaeologists have unearthed the tombs of 71 Yeshuas from the period of Jesus' death. The name also appears 30 times in the Old Testament in reference to four separate characters—including a descendent of Aaron who helped to distribute offerings of grain (2 Chronicles 31:15) and a man who accompanied former captives of Nebuchadnezzar back to Jerusalem (Ezra 2:2).
The answer is actually in the article you linked to.
Contemporaries would have called him Yeshua Bar Yehosef or Yeshua Nasraya. (That's "Jesus, son of Joseph" or "Jesus of Nazareth.") Galileans distinguished themselves from others with the same first name by adding either "son of" and their father's name, or their birthplace. <