BG has some good notes and i'll be reading more on it when i get a chance this week but some notes i've heard are...
1 or 2 CS Stun is VITAL for tier 3 (2 being better just incase)
Dragons in waves of mobs
Elemental Seal Silence and kill fast with lots of Stuns.
Body slam = Pain
Cursed breath + Slam = death/wipe
Void Song (if not silenced) Slows things down ALOT
Most Tier 3 bosses are VERY zergable
Yes even Khim who builds resitance to stun can be CS stunned and Zerged.
Keep these things in mind and GL folks!