Interesting, in the UK polygamy isn't legal, but they do recognize those arrangements as a legal marriage if they were made in other countries where the practice is legal.
I think they should legalize it like this:
Step 1 - 5 year trial, polygamy legal, but only for one woman multiple men.
Step 2 - If more than a dozen people that clearly aren't doing it for tax reasons actually do it, then make it ok for other arrangements.
