To me, the summoner necro was always kind of garbage without sinwar which is probably the biggest design issue with the build. You can get by (albeit slowly) with prebuffing DFT with huonfor and a +skill weapon switch, spamming burning veil, and having an act 5 merc with TU scale mail, clawfeet, and Qarak's Will, but Sinwar was always a make or break item for the build.
Another issue with the summoner (in regards to this patch) is that reducing the number of summons is synonymous to reducing the number of missiles of an AOE attack. It is not just an issue of survivability, but also an issue of killspeed that a health increase will not compensate for. Supplementing a summoner with spells also reduces the killspeed and viability of your summons because their killspeed is largely influenced by black mass since getting to a target quicker means damaging it quicker, not to mention the ITD.
In all honesty, the totemancer has been superior since at least before Laz left, and making a summoner work has always been a bit of a novelty more than anything since summons are such a liability in most of the ubers. I find that odd since necromancers as an archetype tend to summon things.