Besides that, the kidnapping of the Sharan rulers and the scene in PoD, where Graendal believes that Cyndane & Moghedien want to attack her, rather show that Graendal certainly would have used her finest weapon, Compulsion, if she met Asmo, too. This way she could kidnap Asmo, interrogate him about Rand and his plans, and maybe use Asmo as a further tool or eventually kill him.

If anything, this is Graendal's M.O., not just going somewhere without a disguise to kill someone.