Fairy abilities were able to be triggered while casting other spells in ARR and Heavenward. We didn't have a weird oGCD that told our fairy to act back then. You could cast Ruin and tell the fairy to use Whispering Dawn and it happened when the fairy was done casting Embrace. It was a wonderful time even of the fairy had a lot more delay before each commanded action. It just ended up being a situation where you told the fairy to do things earlier. I would gladly go back cause the fairy felt alive as if it had to hear the command, get into position, finish what it was doing, and then start on your request.