Originally Posted by
Ezekielyo
Double mage for lower keys since the orbs only have 250k hp. At higher ones where they have 500k hp, ignite cannot stack fast enough and therefore we need to fireblast/phoenix flames (our instant casts) them to help clear during big pulls where our pala has to heal more. Since PF doesn't work, we are left to fireblast/scorch them losing time and damage. We also only ran 1 mage in the video... Seems you have been bamboozled.
TL.DR - Ignite stacking doesn't help much in higher keys. PF not working does.