You are as obsessed with the number two as traditionalists were with the words man and woman. Can't you see that?
Nope. If you change "husband and wife" to "spouse and spouse" in existing statutes, nothing else changes. Taxes are still the same, marital privilege is still the same, immigration is still the same, etc. In fact, if any existing statute treated husbands and wives differently, it would already be unconstitutional due to discrimination on gender.
But, if you change, "spouse and spouse" to "a group of spouses", then how do you change "upon death of a spouse, the remaining spouse shall inherit 100% of communal property before probate"? As in, you die, and your three widows each inherit 100%? That's 300%. Where do you get two more identical houses?
Or what about medical proxy? You go into a coma, your first spouse says 'pull the plug', your second spouse says 'keep him alive at all costs'. Does the doctor get to decide? Because they can't. Under existing law, no matter what decision they make, the other spouse sues and wins.
In both cases - and in many others - the laws have to change. That's not true for gay marriage, where literally nothing but the label on a line on a form changes.
Marriage is not exclusively about property and inheritance. I can sign a property deed along with someone I'm not married to and I can do the same in my will for inheritance. Man and woman, only two, it's the same type of argument.
You've got it backwards - property and inheritance are not exclusively about marriage. That's why you can also sell deeds and leave things to your children. But yes, marriage is about property and inheritance, which is why when you're married, not only do you not need a will to leave things to your spouse, any such will is irrelevant because you won't even go to a probate court.
"Draft that law, and then you can have polygamy. Until then, not yours."
Exactly what the LGBT crowd was always told until the courts said no.
And what law would the LGBT crowd need to write? None, as noted above. Literally nothing changes in existing laws when there are two spouses, regardless of their genders. Not one single law is different. If you don't believe me, then go find one that has to be changed. I'll wait.
How does it feel to be on the other side?
The side of law and logic? Feels great, just as it always has.