Archery

To make NPC fire at targets first set up a range with however many targets you want and a patrol idle marker lined up at each target:

Uniquely name each Archery Target

Uniquely name each patrol marker

Set up an archery package as in the picture. Use weapon location is the linked to the patrol marker and Target to Attack is linked to the Target Marker. Fill in the schedule tab to what ever times you want - in this example its for 15-18. If you scroll down to the other options you will find minimum and maximum pause options which if set will mean that the archer will pause between shots - taking a random time between the min and max (I set the pause to be between 0.5 and 3 seconds).

Add the package to an NPC - note the NPC must have a bow and at least one arrow in its inventory!