Yeh summon necro plays more like a caster build than a traditional summoner. Instead of stacking spell damage you stack minion damage, which has basically the same effect for night hawks (it's essentially a direct damage spell). On uber bosses with strong AOE attacks that mop up minions in very short time you'll use night hawks only, as it's pretty pointless to keep resummoning stuff that dies in 3-5 seconds. Even with 80k HP, 75% minion resist on gear (max) and 50% avoidance from resurgence. They do have strong damage tho, on regular farming locations they can manage by themselves (Jinn + Abyssal setup). IDK how a veil king version fares because Lazarus set is a bitch to get, i have 400 signets and i've only seen one piece drop so far. I even managed to get the sacred unique demonic head (that has additional 100% life and dmg to VK). Two veil kings buffed by this shield could be pretty strong for bossing, i heard that ppl had their VK facetank hell baal and its minions and not have its hp bar move an inch.
Barbarian minions scale with base points invested into attributes, necro's do not. Never played an endgame summon barb, but it's rather popular, on the server i saw almost as many summoning barbs as 2H melee barbs. I wonder what a level 130 barb with 400 signets and good minion gear can do. I mean farming, not doing stuff like samael or uldyssian.