We start with the loop:
Add a new action and select "For each Integer B, do multiple actions" (under the if/then/else-actions).
Set the '10' to the amount of players there are in your map.
Now the thing you had a problem with: the set loc.
Add a new action inside the loop and select "Set Variable" (above the if/then/else-actions).
As variable, choose "Loc" (which you have created before).
Normally, you would see "Set Loc[Index] = Value" (if you don't, you've messed the variable up).
Instead of the "Index", choose "Function" -> "For Loop Integer B".
For the value, choose "Center of Rect", but instead of the "Playable Map Area", set it to the variable "Region".
Yet again, you will see "Region[Index]", instead of the Index, choose "For loop Integer B" again.
Follow the same steps for the move hero-action and you should have it.