I don't know that her survival actually changed the gravitas of Rand's insanity - even if she did die, she's pretty inconsequential compared to the potential destruction of reality, which is of course exactly why Moridin told Rand how to kill her. Of course, I'm not against Graendal's survival as such, I just don't believe she was supposed to. I'm pretty sure Aran'gar was the one supposed to go after Perrin. It just seems that after all the build up with the Rebels, it feels strange for her to go away without a confrontation, and then be killed off completely casually. Also, there's that male channeler who used the Portal Stone. I don't understand why, if that was just some corrupt Asha'man, they didn't bring enough to actually participate in the battle.

Of course, I have no idea how the timelines were supposed to go. If the attack on Perrin happened before the destruction of Natrin's Barrow, then Aran'gar could have fled there after her failure and then the scene could play out as it did. But I certainly feel something was missing with Aran'gar.