I did look it up and those aren't the same results that I found.
In one case, the men still control the one woman.
"The husband in Kaza, Baldev Nath, 50, said that 'everyone is pleased' with their shared-spouse arrangement, including his older brother and their common wife, 55-year-old Dalma Tashi,
although he did not allow her to participate in the interview."
When two husbands are better than one | GlobalPost
"Positions of power" for the women wasn't in this list:
Causes of Polyandry:
Of course, it is not an easy task to give a generalised picture of the causes of polyandry. Still this form of marriage depends upon certain peculiar local conditions .These is as follows:-
i) Scarcity of women:
Polyandry is found in such communities where the woman population is less than male population. Due to the shortage or scarcity of women a number of men are required to marry one woman. The Todas of Nilgiri Hills practice polyandry due to this reason.
ii) Social Customs:
In some communities polyandry is practiced from time immemorial. It is a custom marriage to them. In Ladakh, for example, polyandry is practiced. Here, woman popularly outnumbered men still the people of Ladakh follows polyandry custom of marriage.
iii) Extreme Poverty:
There exists a close connection between poverty and polyandry. The condition extreme poverty may not permit a man to have more wives or even one wife. Under circumstances he may prefer to polyandry. That probably the reason that in western poor people practice polyandry and rich polygamy.
iv) Bride Price:
High demand of bride-price in some tribal communities is also the cause of polyandry. Owing to the poor economic status a single man fails to arrange the bride price independence hence, the numbers of men collectively arrange bride price and marry a woman.
v) Desire to keep the property intact:
It is said that Ladakhies marry one women just to avoid the division of their Ian property a and houses. The poor people of Ceylon practice polyandry because every far cannot afford to split up into smaller units. Thus, the practice of polyandry is motivated by desire to keep the property intact and to maintain the strength and power of the joint family
vi) Desire to control population:
It is an admitted fact that a single woman bears a limited children. Under polyandry many men marry a single woman. As the children producing capacity of a women is limit hence, polyandry is a very effective method to the people who desire to keep the population under control.
Notes on the types and causes of Polyandry
It's not very common worldwide:
"A comprehensive survey of traditional societies in the world shows that 83.39% of them practice polygyny, 16.14% practice monogamy, and
.47% practice polyandry.
Almost all of the few polyandrous societies practice what anthropologists call fraternal polyandry, where a group of brothers share a wife. Nonfraternal polyandry, where a group of unrelated men share a wife, is virtually nonexistent in human society. Why is nonfraternal polyandry so rare?"
"When multiple men are officially married to one woman, who is 'supposed to' mate with all of them, the co-husbands have very little reason to believe that a given child of hers is genetically his, and will therefore not be very motivated to invest in it. If the children receive insufficient paternal investment, they will not survive long enough to become adults and continue the society. Nonfraternal polyandry therefore contains the seeds of its own extinction."
Why are there virtually no polyandrous societies? | Psychology Today
