Neutral Extra's Vision

I'm making a map where neutral extra is unallied to all players. At one point, there's a sniper that is supposed to attack the players when they're spotted (I have ground flares for Neutral Extra that have a small vision radius). However, the problem is Neutral Extra can see them anywhere; it's like they have no fog of war. I tried creating fog of war with a visibility modifier but that did not work.

Any idea how to give Neutral Extra regular visibility?

you cant.

trigger target accurance on your own.