Help with variables and how they affect individual instances

Hello all!

So I've kinda figured out how variables and picking instances works. I've got a layout with a spaceman who shoots and enemies who respond to him. I've got two instances of the same sprite ("robot") and I've figured out how to use instances and picking to make each instance react individually to the spaceman.

Here's how I've got it set up:

"robot" pick UID

when "spaceman" is withing range ---> "robot" starts firing

So, here's my question. How do I program this so that if I have 20 instances of the sprite "robot" I won't have to create 20 seperate events with 20 seperate UIDs to make all the "robots" act individually? Is there an easier way to do this?

Delete the pick UID, and it will apply to each robot individually.