The main reason our pets don't work (boar/wolf) compared to WD is that ours don't have that nice shiny shield thingy. (I Always forget names haha). Thus, they have no max dmg taken / hit cap like WD pets do, which is 5% I Believe. Force shield thingy. Now this doesen't apply vs dots (chains/desecrator etc etc) because they tick incredibly fast but for tiny numbers, hence never triggering it. http://us.battle.net/d3/en/blog/7029347/7029347#classes
I like the wolf dmg alot but it's too fragile without that force shield passive. And even with it we'd be worse off because we Always have less AR than WD's for example :D
Until they implement DH pets with the force shield thingy, we're best off using the immune-to-dmg pets such as ferret/bat boo.
<- the WD section
<- DH section
From 1.0.4 notes:
"Summon Zombie Dogs
Zombie Dog survivability has been increased:Now also receive 35% of the player’s Maximum LifeThe amount of damage a Zombie Dog can take from a single hit is now capped. The cap scales with the player’s level, and is further reduced by the player’s Armor and Resistance
From 1.0.5 notes:
Added a 30-second cooldown
Reduced each Companion's attack cooldown from 1.5/2 seconds to 1 second
Weapon damage increased from 30% to 38%, but they can no longer critically hit
Companion's damage now scales with attack speedSkill Rune – Wolf Companion
Wolf Companion has been redesigned to be a more durable pet:
Now has comparable durability to one Zombie Dog
New attack: 120-degree Cleave with a 10-yard radius that hits for 94% weapon damageSkill Rune – Spider Companion
Spider Companion has been redesigned to be a more durable pet:
Has slightly more durability than the Wolf Companion
New attack: 120-degree Cleave with a 10-yard radius that hits for 38% weapon damage and Slows every enemy it hits by 60% for 2 secondsSkill Rune – Boar Companion
Boar Companion has been redesigned to be a more durable pet:
Has more durability than the Spider Companion
New attack: Single-target attack that hits for 38% weapon damage
Provides (155 @ 60) Life per second and a 15% bonus to all resistances for the Demon Hunter"
So, the durability, although unknown at least proves that it's possibly
following the same formula. Maybe the Wolf is 35% our max health? 30%? 25%? I don't know, it doesn't say.
From the looks of it health/life is extremely important(for how many hits they can take), followed by armor and res(for how hard those hits are). I'd make a guess that typically, an HC player has 2 to 3 times the amount minimum, of health a softcore DH has.
Softcore DHs effectively ruin the chance of running any other Companions but
the Bat, Raven, or Ferret due to the nature of how gearing is in that game mode.
I'll say this again. Companions can and will survive in higher MPs(earlier on, I once thought they couldn't, until I understood why), the Boar being the most durable, but it's based on their master. The biggest problem they face once you have the defense, are DoTs.
As far as I know, they also share our dodge rating, but I hadn't really tested it. I watched monsters wail on them but sometimes I'll see absorb, and other times I won't see anything but my Companion's health didn't move. Maybe it's a % of our dodge, who knows.
They have the "shield" you mention, because if you watch them take hits "absorb" will pop up on blows.
If your companion dies in only a couple of hits, YOU will die in only a couple of hits.
-Gloom sold separately.
Once you have the defense, Life Regen is one of the biggest complements to Dex/Dodge, since that's a defense vs DoTs, this is why Aid Station is also a welcome addition to Companions as it is for us in general. Spit Fire and Guardian, are not the only Sentries in town.
The Companions also seem to have some form of restoration but I have no idea what it's based off of. A natural regen? Our regen? A % of our regen?