Lesbian feminists frown on polygamy. They prefer having lots of women walking around bemoaning the shortage of good men, hoping that some of them will turn to another woman
Polygamy was around quite a bit in ancient times, mostly a phenomenon of wealthy men. Objectively speaking, it has certain advantages for women in poor areas, in that it's often better to share wealthy man, than to have a poor man all to yourself, from the viewpoint of having a husband who can provide for his wife/wives and children. Personally, I think a culture that encourages successful men to display their wealth by the number of wives and (especially)children they have, rather than the number of toys they accumulate, would do better over the long run than a culture that encourages poor women to "marry" the Welfare State