To define pedophilia, you have to define what a child is. There's an argument whether 16 or 18 should be the legal age of marriage. When the child's age is less than 15, the arguments start to fade away. However when you start arguing that children as young as 10 should be allowed to consent for marriage, you are an absolute moron.
We had a lot of strange practises in old times. A lot of other countries did. We are not in any way better or worse than most of them. However through the process of civilization nations started evolving into better ones. A major key in civilization is the well-being of all people living in a community, especially those who can easily be abused, like people from a certain ethnicity, religious background, women and children. Those groups had nobody to speak for them. Most nations who advance are the ones that pay attention to those little people.
In Saudi Arabia, there is nobody to speak for women or children. Raping a child is very traumatic, and it leaves them with terrible psychological consequences they will rarely ever recover from. For the little girl in the fifth grade, all what she can see and feel in those marriages is a man (usually an old guy) touching her genitals and forcing her into something very awful, very strange and impossible to understand for someone her age. It really doesn't make it any better when the government tells her that she's supposed to live with this abuser for the rest of her life, being under his command in whatever he does. Her only slavation would be if her man picks up another girl from the third grade to be his wife and let her go.
This is child rape. Do not spice it up. Do not defend it.