There's a definite two-headed nickel toss-up.
You said it. As for who's smarter: initially, you would have to give it to Boxer for at least knowing for sure that the man she married was a heterosexual. On the other hand, Arianna was just another new-age guru with an unpronounceable surname before she became the trophy of a closeted oil billionaire with delusions of grandeur. Now, she's filthy rich, available, and a well-known pundit.
I don't know if that would be a two-headed nickel. Sounds more to me like a two-tailed nickel.