You need to release the Time Warden for dodgable fireballs and the Storm Drake for interruptable Shadow Novas.
Everything else is optional, but I recommend getting whelps soon after because of reduced aoe healing requirements.
Your dps looks low. Tank them on top of each other for cleave damage. In my guild, the 2nd target is at 50-80% (depending on when we did it) by the time the primary target dies.