StartCoroutine for each object in a foreach() Loop

I am having some issues getting my head around the Coroutine concept in C#

Question

I have a list of objects that I want to manipulate via a script but I want that action to be preformed a frame latter for each consecutive object so as to reduce the load on the CPU.

My sudo code is as follows:

 using UnityEngine;
 using System.Collections;
 
 public class NewBehaviourScript : MonoBehaviour {
 
     void MainAction(GameObject[] TargetList){
         int Loop = 0;
         foreach (GameObject Target in TargetList){
             StartCoroutine(Action(Loop,Target));
             Loop++;
         }
     }
     
     IEnumerator Action(int Loop,GameObject Target){
         yield return new WaitForSeconds(Loop/2f);
         Target.transform.localScale = new Vector3(0,0,0);
     }
     
     void Update(){
         GameObject[] TargetList = GameObject.FindGameObjectsWithTag("Target");
         MainAction(TargetList);
     }
 }

Any help would be really appreciated!