Scape Scape:
Frankly, polygamy lends itself to sex with minors and should be banned outright on those grounds alone.
That might only be because the groups that practise polygamy also practice arranged marriages and do most of their business behind closed doors. If polygamy were a legal practise, there would be more daylight shone on those who practise it, for example having to get a marriage license, etc would bring the attention of authorities to the marrying parties and prevent the marriage of minors. Right now, this all happens underground in closed communities like the mormon colonies in BC and the US southwest.
There doesnt seem to be anything inherrent about allowing more than 1 spouse
in and of itself that would require or encourage the inclusion of minors.