I will repeat this: I could really care less. What I find repugnant is that they feel they should somehow be "special" because of their arrangement. Apparently, the press feels so, too. But why would society be expected to accept a "throuple" and not a polygamous family group? While only two are legally "married", the third has been "handfasted" to the relationship through legal documentation (read: contract). Now, here's another question; if "handfasting", or the initiation of a contract such as this suffices to legitimize a "throuple", why would such a contract not have been sufficient for other alternative contractual pairings?
Why should I not be able to list my livestock on my tax form as dependents? After all, I house, feed, and provide health care for all of them, don't I? Or is it a prerequisite that one have sexual relations in order to sue for special consideration?
I am unaware of any reason another polygamous grouping cannot use the same type of contract. That is why it is important to remember that the three women are not actually married.
I'm consistently amazed at people jumping from romantic or contractual pairings between humans to similar agreements with animals or inanimate objects. If you cannot see why there is a huge difference between those things, I honestly question whether you should be able to enter into such a contract yourself. It is not a prerequisite that you have sexual relations, it IS a prerequisite that a dependent be human, so far as I'm aware.
But who knows? Perhaps there is some legal loophole which would allow you to declare livestock as dependents. You should look into that.