Why don't you try something cooler than all those hero picker methods, take any unit at all that can attack at range, and give them 0 movement speed and put them in the center of all your heroes. Give the heroes to neutral passive so they don't do anything stupid while we choose heroes. Also make the choosing units buildings (just check that box in the object eitor)
Then make this trigger:
(the condition is: "Boolean Check: Unit - Unit Classification Check & Unit - Unit Type Classification Check")
Code:
Hero Spawning
Events
Unit - A unit Dies
Conditions
((Triggering unit) is A Hero) Equal to True
((Unit-type of (Killing unit)) is A Structure) Equal to True
Actions
Unit - Create 1 (Unit-type of (Dying unit)) for (Owner of (Killing unit)) at (Position of (Dying unit)) facing Default building facing degrees
Unit - Kill (Killing unit) It's that simple :P.
If you want the heroes to spawn at a specific place, replace the value "(Position of (Dying Unit))" which is a region, with a region you created in the editor.
Forgot about having a second trigger that turns off the first one, something like this:
Code:
Turn of Spawning
Events
Time - Elapsed game time is 60.00 seconds
Conditions
Actions
Trigger - Turn off (Hero Spawning <gen>)