When you contrast the first three chapters with chapter 4, you see a huge change in attitude
Pre 4:1, as I see it, these women felt no need for a husband.
Isaiah 3:12 (KJV) [As for] my people, children [are] their oppressors, and women rule over them. O my people, they which lead thee cause [thee] to err, and destroy the way of thy paths.
16 Moreover the LORD saith, Because the daughters of Zion are haughty, and walk with stretched forth necks and wanton eyes, walking and mincing [as] they go, and making a tinkling with their feet:
Whatever the revival is that hits at the end of chapter 3, it appears that the women realize that they are out of Yah’s Devine order in not being under the covering of a man.
They aren’t desperate for sex, it doesn’t fit the storyline. They aren’t desperate for material support, they are already self sufficient and state that they will remain so.
They simply become convinced that they are out of order spiritually, and the only way that they can correct it is to be covered by a husband.
Why 7 to 1? If you run the numbers, you have to slaughter over 90% of the men in order to accomplish that ratio. It makes much more sense to me that 90% of the males left over after all of the wars simply didn’t qualify as adequate leaders of households. The men that were leading families with multiple wives, and doing it well, became the obvious choice. Better many women sharing the best men than having an inadequate leader/covering.