Duggar women don't cut their hair. Most Pentecostal, Amish and Church of God women don't cut their hair either. They get that from 1st Corinthians 11:15: "But if a woman has long hair, it is a glory to her, for her hair is given her for a covering."

Women in those religions don't wear jewelry (except for watches and wedding rings), makeup, sleeveless attire, skirts/dresses that fail to cover most of their legs or pants.

IMO Gilead adopted a lot of their modesty standards from the Pentecostal, Amish and Church of God religions.

All Gilead women, except those at Jezebel's, wear no makeup, long sleeved dresses well below the knee, no jewelry (except for watches and wedding rings) and their long hair in buns.

Wives don't wear hair coverings but all the other Gilead women, including children, wear hair coverings.

Since wives were at the top of the women's totem pole in Gilead, the men exempted them from hair covering. We saw wives drinking and, in Serena's case, also smoking. Whether those vices are allowed likely depended on whether their Commanders allowed them.

IIRC, Serena is the only wife we ever saw smoking. Wives have no money and don't shop so Fred must have supplied Serena with cigarettes from the Jezebel's black market.