Polygamous divorce is normal, if you consider hurt feelings, conflict, difficulties co-parenting, and children acting out as part of a normal divorce experience.
Of course, polygamy is not common and is often outright rejected. It could even be argued "divorce" is not possible by definition as polygamy is illegal in the US. Regardless of commonality, familiarity or legal definitions, I have encountered people living the reality. It happens.
I worked with a polygamous family going through divorce. The experience of the family was similar to the divorce of a traditional first marriage, but multilayered like the break up of two individuals who had married and brought with them children from previous relationships. Multiple combinations of relationships needed to be addressed including the husband/wife, wife/wife, parent/child, and sibling/sibling relationships.
As a representation for understanding the dynamics, consider three adults who had shared a conjugal bed and parented five children together. The man was called, Dad, one of the women, Mom 1, and the other, Mom 2. Prior to joining their families, Dad and Mom 1 had had two biological children together. They married and created a family unit with another woman and her own three. Mom 2 quickly adopted the other two children into her heart and woman as well. Dad led the family and was deeply concerned for the emotional well-being of all members. They lived happily together for some time. Then, as often happens in marriages, one person, Mom 1, felt it necessary to leave.
Like the divorce of a standard couple, this family's divorce was an amoeba dividing, one entity was becoming two. Part of the process was establishing two new family units, identifying who belonged in which, and completing the separation. The solution to improving family functioning was clear definition of the two households, emotional stability, and establishing rules for each. We needed to tailor standard solutions for a non-standard situation.
Defining who was included in which household proved painful. Mom 1 had established a new home and no longer had a bonded relationship with her three ex-stepchildren. The relationship was reduced to a distant wave from the car as she dropped her biological children off at the house now belonging only to Dad and Mom 2. The three ex-step-children intellectually understood, but felt rejected and sought to ground themselves in the remaining family unit. Each time the biological children left the home and returned from being with Mom was a reminder of their loss. I have seen a similar difficult dynamic in situations where mother or father has left and created a new family leaving children behind with only occasional visits.
One set of children moving back and forth between the households stirred sibling dynamics as each child strove to belong and be loved. The biological children, though receiving the most attention by participating in both homes, had the most difficult time. These children were constantly trying to reintegrate as a member of one household or another and often antagonized jealous rejection from the step-siblings. This resulted in another familiar reaction to divorce: exaggerated attention seeking behavior from the children. Dad was so concerned over what was happening that he brought this normally reclusive family into counseling.
In counseling we created concrete solutions for an amorphous situation. Emotions were driving behavior and we needed stability so we addressed those first. Hurt and anger were putting all adults on the defense. The adults found themselves constantly wondering what the other household was doing, how the biological children would react, and how that would affect each day. This gave rise to near insatiable curiosity about the other household. The adults' constant questioning and reactive behavior gave significant power to the biological children. Their undue power and attention further alienated them from their natural family roles as children and siblings. It became critical that the adults curb their defensive curiosity and emotional reaction to the information curried between the households. When they were ultimately able to do this, it effectively reduced volatility and reinforced the definition between the two homes. This stabilized the environment and put the power back with the adults.
Once the two households had been separated and emotions channeled, the family focused on re-establishing routine and normalcy. A significant source of problems was common household chores. It felt highly unfair to the three children in the home that the siblings who got to leave would get out of picking up the dog poop, helping with the dishes or other similar duties. Dad and Mom 2 led a family meeting to discuss and renegotiate who did what and when. Rotation of weekly chores was clearly established and whenever possible everyone helped clean at the same time so the two commuting children were able to be fully integrated.
Finally, it also became necessary to ban expensive toys and clothes from being brought from Mom 1's into Dad and Mom 2's household. It was difficult for the three siblings who share the financial resources of a seven member family to not be envious of the clothes, toys, or entertainment opportunities of the others. Leveling the field among the siblings further reduced rivalry, improved the degree of inclusion of the biological children in the family, and increased the peace by clearly defining the two homes.
The divorce experience of a polygamous family was complicated due to the number and intensity of relationships involved. They were uncommon individuals who made unorthodox choices, but their pain and difficulty in the process was not unique. They were successful in addressing their challenges by using skills traditionally employed in divorce situations. Defining and respecting boundaries, maintaining emotional control, and establishing stability in the home helped the children feel more secure and smoothed the painful transition for everyone. All this is easier said than done, I understand. That's why I have a job.