In normal difficulty you will have 2 Sanctum Sentry. Each Sentry has an aura that will increase the other pack member's damage by 50%. Sentries have a stacking bleed effect that will cause a lot of additional damage to heal through. Your raid will also require special positioning so as to maintain range to avoid pounce, but be able to react to void zones.
Alternately you can have a healer/tank offtank the Sentries away from the raid while your maintank covers the Defender. Be mindful of maintaining your raid outside of LOS from the sentries.