i think this would work, you need to add as many players in the event as you want affected by this trigger with size needs to be changed to the distance away you want the unit to be able to attack from. there may be a problem where this region doesnt actually exist, i dont know i havent teseted it. report back whether it works or not.
[trigger:1:7e474e1cb6]
Untitled Trigger 001
Events
Unit - A unit owned by Player 1 (Red) Is issued an order targeting an object
Unit - A unit owned by Player 2 (Blue) Is issued an order targeting an object
Unit - A unit owned by Player 3 (Teal) Is issued an order targeting an object
Unit - A unit owned by Player 4 (Purple) Is issued an order targeting an object
Unit - A unit owned by Player 5 (Yellow) Is issued an order targeting an object
Unit - A unit owned by Player 6 (Orange) Is issued an order targeting an object
Conditions
(Issued order) Equal to (Order(attack))
((Owner of (Targeted unit)) is an enemy of (Triggering player)) Equal to True
Actions
If (All Conditions are True) then do (Then Actions) else do (Else Actions)
If - Conditions
((Region centered at (Position of (Targeted unit)) with size (0.10, 0.10)) contains (Triggering unit)) Equal to True
Then - Actions
Do nothing
Else - Actions
Unit - Order (Triggering unit) to Stop
[/trigger:1:7e474e1cb6]