Sanguimancer Demon nerfed (or bug)?

I bought 5 Sanguimancer Demon, and I noticed that they HP is always going down, seems like they are not healing each other.
I tried:

- United in Dream (Minion Leech 5% of damage against poisoned enemy);
and
- Feasting Friends (Minion Leech 0.4% of damage as life);

But in two or three group of monster they run low of HP and start to wander around without attacking. Against bosses they stop at 1/4 of the fight and take a good time for they to start attack again.

EDIT:

https://www.youtube.com/watch?v=5w8R_AUE30U

In this video the Sanguimancer Demon is sustaining each other.

I give up, they died, even with Minion Life Regen and Life Regen Aura they drain their life and only start to attack again when full HP

I gave it another chance, and I managed to make they "sustain" itself, here what you need:

- A lot of minion regen, Righteous Army, Sacrifice, Decay Ward and Vitality Aura;
- Minion Defense Mastery: Minion recover 5% of life on minion death;
- United in Dream (5% Leech);
- Feasting fiends (0.4% Leech);
- EDIT: Leech from Minion Defense Mastery;
- Spam Convocation;
- Spam skeletons to trigger Minion Defense Mastery in emergencies;

Yet, if you have too much Minion Casting speed the Life Regen will not be enough and they will start to die, and since you spent too much on defensive nodes they don't have damage.

In the end the big advantage of this spectre is nullified. I tried, and I hope someone find a good use for this spectre.