Their CC chain can lock down one of your DPS entirely - Blessing of Protection or Freedom the target being trained to buy time.
Kiting casters are hard for two melee to pin down - use Hammer of Justice/stuns on the healer specifically to create a burst window.
Similar melee-cleave mirror - whoever lands the first full stun chain on the enemy healer usually swings the fight.
Same shell on both sides - whichever team lands its double-stun on the enemy Shaman first usually forces the winning trade.