On encounter mobs, root main mob, have pet tank and kill the adds, then focus on main mob, re root and summon a new pet when your current pet dies. Takes maybe 30 sec for a necro to kill a triple up of corrent or higher level. Could be faster depending on gear. I was in RoV rolling a lowie and there were 4 instances filled with necros with names like oaiaosiaosioli. The wave is coming.