Why would such stately women be complicit in such a scheme? Why would they give up their power and freedom to a hierarchical system that clearly disenfranchises women and children? Obviously the women get something out of it. They get to live their religious beliefs (providing this is what they've chosen to believe, rather than something they practice just because their parents did.) For another, they marry into a committed partnership reinforced not just by two people, but by several people. A polygamous wife marries her husband and her sister-wives, in a sense. Despite the potential for raids and the possibility that families will be broken up by the state, plural marriage provides more predictable odds for success than monogamists who face a divorce rate of two-thirds to three-fourths.
Women attracted to power can actually maneuver their way into a prime spot in the polygamous pecking order. Such a woman may have more power in the family than anyone other than her husband. And if a woman uses her wiles, she can exercise more power than the head of the family. I knew one woman, a first and legal wife, who lost all her authority to the fourth wife who'd learned at an early age to use sex to manipulate men. Her husband did what the fourth wife wanted no matter how much contention the inequity caused among his wives and families. Even though fundamentalists insist that religious tenets govern this way of life, those with a bead on reality know that even a pious patriarch has both an ego and a body—both of which like to be stroked. A woman who wants to bend the patriarch to her will knows enough to do lots of stroking until, like the horse who bends to the careful handler, he becomes her ride to power. Then the only person in the fundamentalist community she must deal with is "the prophet." And if she keeps speaking the party line and singing a song pleasing to him, eventually she'll have a public voice and people will listen. From there she can lift up the prophet or bring him down. Then she can decide, whose next?