Bais yakov maidel, I’m sorry, but that’s also hogwash.
The reason a woman can’t have multiple husbands is because once she has one, she’s an eishes ish, and kiddushin isn’t tofes. That’s lomdish speak for “because Hashem said”.
Any social reason you’ll try to give is going to be incomplete and dangerous.
Is it okay to have multiple husbands now that we have genetic testing? Is it okay if her husband hasn’t been seen in years but never gave a get? Is it okay if he’s in a hospital lying in a vegetative state?
No, because she’s still an eishes ish.