Detecting Object On Tile

I have a turn based strategy game for mobile, and the movement is based on tiles. I have a system setup so that it shows which tiles can be moved to, but I want a method to say which tiles you can attack, and I want to mark it by setting a sprite to active. To accomplish this the way I though of, I need to know which soldier is on each tile, if any. So how would I do that. Important scripts attached:

Movement: using UnityEngine; using System.Collections; using System.Collections.Generic;

 public class MovementController : MonoBehaviour
 {
     public int moveRadius;
 
     public GameObject[] tilesInGame;
     public List<GameObject> tilesToMove = new List<GameObject> ();
     public List<GameObject> tilesToAttack = new List<GameObject> ();
 
     public GameObject moveTarget;
 
     public bool canMove;
 
     private DefaultMenuManager defaultMenu;
 
     void Start()
     {
         defaultMenu = GameObject.FindGameObjectWithTag ("GameManager").GetComponent<DefaultMenuManager> ();
 
         tilesInGame = GameObject.FindGameObjectsWithTag ("Node");
 
         canMove = true;
     }
 
     void Update()
     {
         
     }
 
     //Update Targets for Movement
     public void MoveTarget()
     {
         DisableAllTiles ();
         AssignTilesWithinMove ();
         ShowTarget ();
     }
 
     void DisableAllTiles()
     {
         foreach (GameObject tile in tilesInGame) {
             tile.GetComponent<Node> ().targetMarker.SetActive (false);
             tile.GetComponent<Node> ().canMoveTo = false;
 
             tilesToMove.Remove (tile);
         }
     }
         
     void AssignTilesWithinMove()
     {
         foreach (GameObject tile in tilesInGame) {
             if (Vector3.Distance (transform.position, tile.transform.position) < moveRadius) {
                 tilesToMove.Add (tile);
             }
         }
     }
 
     void ShowTarget()
     {
         foreach (GameObject tile in tilesToMove) {
             tile.GetComponent<Node> ().targetMarker.SetActive (true);
             tile.GetComponent<Node> ().canMoveTo = true;
         }
     }
 
     //Update Attack Markers
     void AttackMarkers()
     {
         AssignTilesWithAttack ();
     }
 
     void AssignTilesWithAttack()
     {
         foreach (GameObject tile in tilesInGame) {
             
         }
     }
 
     //Move Soldier
     public void MoveSoldier(GameObject tile)
     {
         MovePosition (tile);
         DisableAllTiles ();
     }
 
     void MovePosition(GameObject location)
     {
         Vector3 offset = new Vector3 (0, 0.375f, 0);
 
         transform.position = location.transform.position + offset;
 
         canMove = false;
     }
 }

Node:

 using UnityEngine;
 
 public class Node : MonoBehaviour
 {
     public enum TileType
     {
         GrassField, ShallowWater, DeepWater
     }
 
     public GameObject targetMarker;
 
     public GameObject soldierOnTop;
 
     public TileType tileType;
 
     public bool canMoveTo;
 
     void Start()
     {
         soldierOnTop = null;
         targetMarker.SetActive (false);
         canMoveTo = false;
     }
 }