NAF – New artifacts with unique properties.

Is it possible to configure the game so that a specific artifact appears on the map only once? It seems strange to have more than one Marquel's Skull, and, for example, the Sword of Compulsion (from Heroes 6), mentioned in the post above, also shouldn't be able to be duplicated – it was forged in a single copy by the Archangel Sarah from Urgash's claw, and so on.