It seems Outland’s denizens have gotten quite a lot weaker in the armor department! There’s a bug going around that’s dramatically reduced mobs’ armor, greatly benefitting physical damage classes, but Blizzard are now aware of it. A fix is coming soon, with the next realm restarts.
Can confirm.
Yes, there is a bug causing enemy armor to not work as intended and yes, we’re fixing it very soon.
We already have a fix in flight, and it should clear up the bug the very next time we do realm restarts.
And the fix will appear in our hotfixes update thereafter.