Pyrrhotite will generally always occur in more abundance than...

Pyrrhotite will generally always occur in more abundance than pentlandite/chalcopyrite. Thus, when sulphides are present, it is the pyrrhotite which is driving the EM response, whether the good stuff is there or not. Pyrite can also be a good conductor sometimes. You just have to hope for the best with the drill and it is pure luck (maybe guided with soil sampling) whether the Ni/Cu sulphides will be there in association with Fe sulphides.

Anyway, this is a decent announcement and builds a bit more confidence that there might be sulphides present. Note that a couple of these conductors (20a and 10a) overlay previously announced ones in map view (not sure about vertically). Not that that's a bad thing, multiple lines confirming the same thing. Just remember to compare with other results.