All of the parallel stories are actually illustrations for our benefit. They reveal God's overall plan in the Great Controversy. Especially these stories are to be understood by God's people at the end of time. In reading the stories in the Bible we can now see not just a random collection of interesting stories that we can tell our kids, but a repetition of the same theme which explains God's purpose throughout history.
The parallels are just too close and too numerous to write off as mere coincidence. God wishes to teach us our history as humans and as His chosen people.