PissMark does not in any way or shape tell anything about IPC which is all that matters for WoW. It's 99% multithreaded/office application test with no relevance whatsoever in gaming.
Still the clockspeed does not tell anything about actual performance between two different brands. Not with nor without turbo. And FYI i3/i5/i7 CPUs do the exact same turbo thingy as AMDs processors, upping speed and shutting off cores.