Hi thank you for your reply.
I figured out that 'Get Next Child' action is handy for such situation.
To answer your question, these objects will pre-exist in the scene but originate from a prefab. There wont be any spawning.
I used Get Next Child in a loop and added all those objects under a parent. Then I used classic 'Array Add' within the loop.
So far this works, and hope it will continue to do so.