I just wanna chime in here and say that the SCH fairy has her own enmity, and it's not uncommon for her to pull aggro when using Whispering Dawn at the start of a pull (at least around level 30 where I am). So from a SCH perspective, the issue is more that enemies occasionally run away from tanks while they're building aoe enmity at the start of a fight. I've never seen it pull a tank's primary target.