Magician Greater Con. VS Vorocate

[Feanol]

Pretty straightforward question here I hope someone with better experience can help.

If I have the Shovel on Ponz but not the Staff of Elemental Mastery: Earth, does it make more sense to cast Greater Conjuration over Vorocate?

It's my understanding that a focus item gives the pet a 25% increase in hit points. This would make a max-level 49-spell pet have 3625 hit points. An Earth pet summoned with Vorocate would max out at 3150 since I don't have the 50+ focus staff.

Is the added damage given by the Root DD really worth having a pet that can take less hits? Does the pet's overall higher level end up negating a lot of received damage anyway? I'd appreciate any input or conjecture you folks have.