you make 2 loops now
1 you are making up the array on point
2 place the actors
you will not get over lapping objects.
before you find a point check that you do not over lap any objects then place the object.
now you can not tell if an actor of the current type is there or not as you are find the point then place the object.
I hope you understand want I am say, if not I will try and reword it.