Zelkor is the only person who thinks the Mantid and Zerg are the same. Read up other people's posts and the Lich King is more like the zerg.
Pandaren were barely known back then. All we knew about them were that they loved adventure, brews, and lived on a Island.
Where did the idea Mogu come from? Or the Sha? Vermin? Grated they are similar to Kobolds but are unalike at the same time.
So other than one guy thinking Mantid are zerg, what other concepts are "cut and paste from other projects"? In MoP of coarse.