Children and parents in relative space

My question is mainly: If objects are grandchildren, does that effect transform.position, this.gameObject, or GameObject.FindGameObjectsWithTag()?

To elaborate, I have lots of empty game objects that I'm using to detect cover in a stealth game. These empty game objects are children of walls which are, in turn, children of prefabs that include the walls and floor. Using the code below, I am trying to find the end of walls. It is giving me lots of funky points and null values though. If the child/parent relationship wouldn't effect anything, the question becomes: What am I not understanding? because I've gone over the logic a hundred times and don't see a problem so I can only assume I'm using a command wrong. Thanks for looking!

~Rangr

(Assume that FindClosest works and does what it sounds like)

(Also, I repeat for each cardinal direction starting at the first if statement but it's the same code for each with directional changes)

 List<GameObject> lefts = new List<GameObject>();
         List<GameObject> rights = new List<GameObject>();
         GameObject[] obj = GameObject.FindGameObjectsWithTag("Cover");
         foreach(GameObject go in obj){
             if(go.transform.position != transform.position && (Mathf.Round(go.transform.eulerAngles.y) == Mathf.Round(transform.eulerAngles.y) && Mathf.Round(transform.eulerAngles.y) == 0f))
             {
                 if(go.transform.position.x == transform.position.x)
                 {
                     if(go.transform.position.z < transform.position.z)
                     {
                         if(FindClosest(GameObject.FindGameObjectsWithTag("Cover")).transform.position != transform.position)
                         {
                             lefts.Add(go);
                         }
                     }
                     else if(go.transform.position.z > transform.position.z)
                     {
                         if(FindClosest(GameObject.FindGameObjectsWithTag("Cover")).transform.position != transform.position)
                         {
                             rights.Add(go);
                         }
                     }
                 }
             }