How can I most efficiently kill a primordial scavenger?

I just made it to the Battlefields of Eternity in Act 5 with my Barbarian and Primordial Scavengers (particularly elite versions) are causing me a real headache. They aren't much of a threat in terms of damage they do, but it just takes forever to kill them. They've got rocky coverings that seems to block all damage until at some point (randomly? after enough hits?) they lose their armor and become vulnerable. At that point, for normal ones, I can usually kill them before they burrow beneath the ground and get a new set of rocky armor. However, for elite ones, sometimes I have to go through this process a half dozen times and it's just painfully, painfully slow.

Is there a trick to knocking their armor off or otherwise dealing with them more quickly?

Solution 1:

So far in my experience, I haven't found a way to get through their blocks. Since they don't hit too hard, I usually just hit them until their armor comes off with weaker attacks, saving my control and harder attacks. Once it comes off, I use my stuns/freezes/disorients/etc to keep them in their unarmored form for as long as possible while I nuke them with my hard hitting abilities. For elite packs, I try to focus on one at a time so that I can make sure I maximize my damage while they're unarmored. They're still a pain, especially when they're extra health, shielding, and/or illusionist.

Solution 2:

As a barbarian I found bleed really effective for striping the armor as it hits for small amounts over time continuously. So any quick rapid attack should be used for removing armor then a good solid power attack to finish the weaker version.