Enemy Attraction/Aggro

I have been trying to have my enemy react to the player and if there are any nearby enemies wit$$anonymous$$n its sphere collider trigger that those enemies will also be aggroed and target and chase the player. If there is a better way of handling t$$anonymous$$s kind of behavior then please let me know since I am still learning how to develop games and using unity. Here is the script I have so far.

public class Enemy : MonoBehaviour {

 public bool gamePaused = false;
 public bool isAggroed = false;
 public GameObject player;
 public bool inSight = false;
 
 // Update is called once per frame
 void Update () 
 {
     if (isAggroed == true)
     {
         if (Vector3.Distance(player.transform.position, transform.position) > 3)
         {
             transform.LookAt(player.transform.position);
             rigidbody.velocity = transform.forward * 5;
         }
         else
         {                
             rigidbody.velocity = transform.forward * 0;
         }
     }
 }

 public void OnTriggerEnter(Collider collider)
 {
     //Debug.Log("Enter");
     PathFollowing continuePath = transform.GetComponent<PathFollowing>();
     if(collider.CompareTag("Player"))
     {            
         continuePath.followOn = false;
         //inSight = true;
         isAggroed = true;
     }
 }

 public void OnTriggerExit(Collider collider)
 {
     //Debug.Log("Exit");
     PathFollowing continuePath = transform.GetComponent<PathFollowing>();
     if (collider.CompareTag("Player"))
     {
         continuePath.followOn = true;
         //inSight = false;
         isAggroed = false;
     }
 }