Overall? none…
…and there are easily 50 other colleges and universities who are not in that particular sports league that are at least as good in “Humanities & Social Sciences” as any of those 3, and for any particular aspect of H&SS there are ones that are better.
For example, if you are looking at International Relations, I would look at Georgetown, JHU and Tufts before I would look at any of those 3. If you are looking at Creative Writing I would look at UIa, NU, Kenyon or Emory before Dartmouth or Brown. If I wanted a strong Core curriculum across the Humanities I would look at Columbia or UChic before Brown. And so on.
If you are thinking that these schools are the “easier” way to get the “Ivy” label please re-think the whole thing.