It seems to me that Hannity wants to really be Rush Limbaugh but that chair is already filled. Also, Hannity is a parrot for the Republicans. If Trump had run as a Democrat, Hannity would have hated him.
Greta Van Susteren seems to be more of an enigma. In an age of narratives and "die on every hill" politics, she seems to be above the fray. She can cover a breaking story or grind out a political issue. In the end, I suspect everyone will dislike her because she doesn't always set her pike on their side.