When it comes exploring the open world, i belive there will be zone levels. Since Scosglen is the starting zone, mobs die easier BUT they really need to put some challanges. For dungerons, they might put Normal, nightmare, hell and chaos for endgame. Rember that this is an open world Action RPG + MMO and they cannot force torrent difficulty levels in open world zones since every one slaying mobs all the place.