Graendal's idea is simple, and shows why she was so good at her job. She considered the possibility that Nynaeve could read compulsion. Which meant that through her, Rand would be able to glean her plans. She clearly expected that Rand's next move would be based on what he thought Graendal's plan was, which he would interpret from what she wanted Ramshalan to do.

She wanted to delay him, so she had Delana compel Ramshalan and give some random orders. Since the orders aren't from Graendal, Rand would obviously be confused, or ascribe weird motives to her, either of which suited her since it would delay him from attacking her. She added to the confusion even more by having Aran'gar do some saidin compulsion.

That she took such care was rewarded. When she saw that Rand had meant to use the compulsion only as an indicator of her survival, she saw the chance to appear dead but be actually alive.