If you have the quest "Sack Tor Aendris" and place "Naggaroth Spearmen" on are you able to use its Action ability?

Sack Tor Aendris states "Any unit Questing here may attack as though it were in your battlefield." And if so is it useful?

I believe the discussion, which originally was Defend Tor Aendris + Swordmasters of Hoeth (unit Questing can defend any zone, would SoH still benefit if they were questing and defended the BZ?) that the unit has to be physically in the zone in question. So Naggaroth Spearmen have to physically be in your BZ, ditto for Swordmasters, for their abilities to work.