Isn't adding more people making the marriage unequal? If you have 3 wives, the marriage is no longer a 50/50 split. While the wives are dependent on you as only husband, you can lose one and still have two. I don't de how this doesn't lead to inequality in the relationship.
Isn't that dependent on the nature of the relationship?
You seem to be making assumptions about how a polygamous marriage must function that don't make sense to me. Why must it be one husband and multiple wives? Why must the wives be dependent on the husband? Why can't the husband and other wives be dependent on one wife? Why can't it be multiple husbands and one wife, or multiples of each?
I will agree that polygamous marriages would require a whole lot of changes and additions to current marriage law. I can also agree that it would lead to many problems as people either fail to anticipate certain situations or assume that the rules for all situations are already settled. The fact that it would be a complex issue doesn't automatically make it one to ignore, however.