Speaking for Coast Salishan peoples and neighboring groups in the Southern Northwest Coast, it doesn't appear have been a particular issue, but this can be attributed to the fact that historically, these peoples overwhelmingly preferred exogamy (marrying outside the immediate group).

#General Social Background

Like every other society on the Northwest Coast, Coast Salishan peoples like the Puyallup, Tsleil-Waututh, Duwamish, Lummi, and others, had a social structure that resembled the following:

Nobility - Extended families and lineages with long established good reputations, keepers of certain prestigious rites/rituals/powers/etc, wealthy in both material property (though not always) ​and immaterial property such as songs, respectable pedigrees, wide intertribal connections. Almost always married to other nobles.

No-Account - The lower classes with varied backgrounds, but tend to be the descendants of freed slaves or perhaps refugees. They tend to be seen as lacking the good manners, history, and other familial aspects such as songs, prayers, and rites that would have been omnipresent among the nobility. Usually married within the same tribe to other people of no-account.

Slaves - Slaves are human property, often captives from foreign lands who have had the misfortune to be reduced to the bottom of society. Married amongst themselves, though free men occasionally married their slaves.

Marriage as a rule was the forming of an alliance between families. Whether it is to reinforce already present ties in an area, procure new allies, or ease tensions, marriage was seen as a method to peaceably establish long term diplomatic ties between families.

#Polygyny

Marriage among the nobility usually took the form of polygamy wherein one man had multiple wives, this increased the economic power of the household by bringing in more members who could produce items like blankets of wool/dog wool/woven cedar bark/fur, baskets, clothing, delicacies (dried clams being a particularly sought after commodity by visitors from the Columbian Plateau), and occasionally products of professions more traditionally associated with males like carvings, weapons, and associated tools or materials. This economic boost compounds with the alliances that have been formed with the family/families involved, introducing new opportunities for goods that might be rare and difficult to procure in one place or gaining a new family to support the husband or his relatives in tribal politics whether it be war or tribal council.

Thus, marrying multiple women would not only increased the economic power of a household, it brought about new reciprocative economic opportunities for that household and socio-political support from abroad.

#Exogamy

This leads to what would alleviate the potential of diminished available women being married off to one man as was the case in an episode of "Squidbillies" on Adult Swim. Since marriages are alliances between families, it would be better to establish an alliance between families of different tribal groups than within the same tribe. As a result, one village would be unlikely to have all their single women married off to one man that called "dibs" on them before anyone else since he would have gotten more from other villages and tribes. Whether those other villages and tribes were close neighbors or further

As I noted earlier, these peoples prefer marrying those of other tribes, and there is plenty of evidence both historical and contemporary to support the idea that this has been a longstanding practice among them. A local and personal example would be the very common marriages between Southern Coast Salishan tribes like the Puyallup and Duwamish with Sahaptin speaking peoples like the Yakama and Klickitat.

#That All Being Said...

While it would be infeasible for a village or tribe to find itself nigh-barren of marriageable women for the bachelors looking to settle down out there, individual household families might find themselves down a few sisters, cousins, sister-cousins (this isn't because of Crusader Kings shenanigans) because it was considered best to have wives that were related so that the chances for strife between wives within a household is limited as much as it can be; as such, the line between sister and cousin could be nil. This may seem counterintuitive considering all that has been said about the interest in maintaining or establishing intertribal alliances, but this is a consistent piece of advice for the aspiring polygamist. Try to keep your wives from the same family, preferably sisters, because they have a reason to be civil and kind to one another.

Now, one might be curious as to how much ruckus could unrelated women married to one man bring? A lot.

No holds barred fights, bullying, one wife driving out others, and attempted murder are cited within one example of a Chehalis man that started out with four wives and ended up with one as the others left. While violence between men over a woman is of course present in Coast Salishan society, violence between women over a man is also present to a substantive degree as well.

Sources used:

• Evergreen Ethnographies, compiled by Jay Miller (2015).

• The Puyallup-Nisqually, by Marian Smith (1940).

• Indians of Puget Sound, Haeberlin and Gunther (1921).