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Polyandry would only worsen the poverty, cause social deterioration and decrease overall socio-economic living standard of the Pimbwe society, provided there's actually a large economic potential in Pimbwe, which it appears to have inferring from the article.
Polyandry is only practised in areas where land resource is severely limited and land size is quite restricted, which notably impacts an offspring' survival rate, so polyandry is typically seen in mountainous regions, as it's wiser to focus all the effort in bringing up a single child that has fairly good chances of surving than having many children who will end up not surviving adulthood.
As such, in the mountainous regions of Nepal there's a tiny community that actually practises polyandry.
However, among humans, most polyandry that exist is only the fraternal type. Fraternal polyandry is when brothers marry the same girl, as both male partners are genetically invested in the offspring, so both are 'motivated' to help raise the child together.
It also facilitates easy inheritance of the limited land owned by these men in this region.
Therefore, unlike polygyny (one male with several female mating partners) which unsurprisingly has the exact opposite biological reproductive effects to polyandry and is also widely practised among humans, commonly observed even today, the evidence of polyandry practice on the other hand, is fairly rare and often only observed in the societies' fringes where resources are limited.
Besides, the potential of polyandry to decrease a society's population willn eventually result in stagnation of the overall socioeconomic progress in that society. Furthermore, from an evolutionary point of view, male-male competition and intense male sexual jealousy combined with uncertainty of paternity if female promiscuity is high, makes it virtually impossible for polyandry practise to develop widely in human societies.
Likewise, polygyny is the most common mating strategy seen among mammals, with up to 90% of mammalian species engage in polygyneous mating.
It's also worth pointing out "serial monogamy" mating strategy, particularly seen in affluent western societies and among Hollywood celebrities, significantly benefits men's reproductive success more than women's due to men's notably longer period of biological ability to reproduce, as demonstrated by the data from several different studies.
Example, it's more common to see older wealthy men having younger wives than the genders inverse. Besides, it's not uncommon for men's mate value to increase as men grow older, due to increasing status, power & wealth.
Moreover, serial monogamy is definitely not the same as polyandry, as the latter involves one woman married to more than one man at the same time. These two very distinct mating strategies seems to somewhat be equated in this article especially from a reproductive and fertility point of view.
So, I don't really see how polyandry is going to benefit Pimbwe as the article claims or benefit any society for that matter, with exception for the atypical few societies.
