Might help, might not.
I went to one of the Brazil servers, and started a DK. Got him to 58, took him to Darnassus, flew him to Felwood, rode over to Minfernal Central™. I saw the best little icon show up on my minimap. I walked over to this cute Minfernal running around. It was the best thing I've ever seen. He was common, but HE'S MINE!
There was only one, but that was good enough for me! I'm leaving him camped there so he can continue hunting for a rare, or the upgrade stones come out, whichever is first.
It is fast to level a DK far enough to get out of the zone, and move him to a spawning point. Try this on a couple servers and try your luck!