That chart is a bit out of date, the new wow expansion updated the graphics engine a bit.
Wow prefers a high speed cores but few of them. I was running on a VM on a e5-2676 v3 (12 core, up to 3ghz), 6 cores assigned to the VM and a GTX 970 video card. During the legion invasions (tons of people and enemies on the screen) one core was maxed out, gpu usage was low, under 50%. I would get 25-30FPS running at 2560x1440 settings on "7" which is the old Ultra settings. Faster video cards did not make it better. Running bare metal did not make it better.
I built a i5-6600K overclocked to 4.2ghz and was getting 55-70fps with the same GTX 970, display settings and legion invasions. GPU usage is now in the 80-95% range.
EDIT: Wow seems to run on pretty much anything but if you want the best experience it still needs a pretty stout computer.
Also take a look at this:
It really comes down to your what games you play or apps you run. If your software doesn't scale well faster with less cores may be better.