Incorporeal Nethrim & Non-Ferrous Weapons

[Dorn]

Unsure if intended, or some side-effect of changes in the background but while they've always been tough to deal with using Non-Ferrous weaponry they currently seem to be immune to damage from at least Bronze completely?

Are Corvites & Tainted supposed to have another material to deal with them (as in an actual weapon), or is it just torches? That is, if this is an intended change!