But polygamous behavior also precedes wars...as when it is prescribed by the values of the prevailing norms such as those allowed by the religion such as with Mormonism and Mohamadenism.
There were no wars attached to Mormon polygamy. It was quite practical for the 50 years or so it was practiced. There were more female converts than male. The Mormon population was isolated in Utah. It was a convenient way to provide security for unattached females.