no, i mean it doesnt necessarily mean it's just them. There was other races there, Taunka, Tuskkar, humans(i think, never did the quests by Naxxramas or that forest with the tree) Vrykul, and im sure a couple others, and the trolls, but Drakkari were all north of where Arthas would have been, and he got these mercenaries over where the ships were, which could have been howling Fjord iirc.