If he were legally married to all of them, the wives and children would be eligible for death/disability/social security benefits should something to happen to him, but they would also be entitled to those same benefits even if they aren't all married to him if the children were adopted by him or were his natural children. If the women are working to support themselves and their children, that would be the only way all income would be counted whether they are married to him or not.
If they aren't married to him, and none of the children were his naturally then they are all entitled to welfare benefits (but the daddies whoever/wherever they are, should be responsible for paying child support). If the women are working, then their income, plus the child support, would be the only income counted.
Since you stated that they are all collecting welfare, the assumption has to be made that 1) none of the women work 2) none are receiving any social security/disability/unemployment/death benefits and 3) none of the daddies are paying child support.
Wonderful.........and you still would approve of a polygamous marriage because 'it doesn't bother you' that taxpayers are supporting them all or that they even consider themselves married? Quite the liberal, aren't you? Sounds to me like the man is the only one making out (literally) with many cows around that are actually supporting HIM on taxpayer money because no matter which house he goes to (assuming they live separately), he's well fed, has a roof over his head, and all utilities paid for without any effort on his part at all. If they all live together and each mother is getting welfare for herself and her brood, I've never heard of that type of arrangement being legal with regard to social services' benefits they receive....not to mention Medicaid/Obamacare for all.....
What part of any of this don't YOU understand?