Guard NPC in Traitor's Passage doesn't fight mobs

The guard NPC in front of the crossbow in Traitor's Passage doesn't fight mobs when moved into the cave. I tested with Skitter Golems, Quake Golems, Risen Maraketh, and Black Striders. Out of the above, the guard killed the first 3 but did not fight the Black Striders when pushed into the cave entrance. Also the guard on the left is useless and I couldn't push him at all.

To reproduce, you can use the Tempest Flurry skill with some attack speed to push the guard in front of the crossbow.

Also, if possible, could you add NPCs to every map. My build depends on this. Thank you.