As anni marauder:healing debuff->interrupt->next heal->force choke->next heal->interrupt->next heal->charge->next heal->interrupt....all they while i keep dots on him and use some nukes...healer dead.Healing merc is different story tho.
Its not over and over,its once in 12-16 seconds and prone to failing.And in between he cant do much.Guess what?il do more damage as anni in those 12 seconds.And carnage specced mara(as bad as carnage specc is) can do a ravage that will do 6-7k in seconds.
Anni have ramp up time as you need jyuo stacks for damage and dot crits.Your dots wont kill anyone by themselfs,neither will annihilate and vicious slash will.Its damage from dots coupled with follow up with annihilate and vc is what will gib someone.