World War 3 maps are a type of maps, like footmen wars, vampirism, hero line wars, that are being played on RoC battle.net (they are played less than the maps just mentioned, but you see them every now and then). And that's just what they are, i dont know who or why he named them like this, it's just how it is. Go on RoC battle.net, and you will see that all the maps are like this one (altough usually slightly smaller terrain, maybe unbalanced units, and custom heros that can be made infinite times).
Also, there arent really Goblins in europe. 1.) The goblin engineer is found in greenland or Turkey (asian part), and second, its just what i call them since the builder you have to buy is a goblin, and bought at a goblin building. The units are only machines (zeppelins, shredders, or custom models)