Animator override script is not entirely read

I have several enemies and I want to make only one animator for all of them. So, the animator need to be overridden for each enemy. I have done this script:

 public class EnemyAnimation : MonoBehaviour
 {
 
     public AnimationClip[] animationClips;
 
     private Animator animator;
     private AnimatorOverrideController animatorOverrideController;
 
     public void Start()
     {
         animator = gameObject.GetComponent<Animator>();
         animatorOverrideController = new AnimatorOverrideController(animator.runtimeAnimatorController);
         animatorOverrideController["Move"] = animationClips[0];
         animatorOverrideController["Move_Right"] = animationClips[1];
         animatorOverrideController["Move_Low"] = animationClips[2];
         animatorOverrideController["Move_Left"] = animationClips[3];
         animatorOverrideController["Attack"] = animationClips[4];
         animatorOverrideController["Death"] = animationClips[5];
         animator.runtimeAnimatorController = animatorOverrideController;
     }
 }

The issue is that the last line is never reached. Sometimes the code stop at the line of ["Move"], sometimes at the line of ["Death"]. This is not due to an error of compilation or others. It's just that the other line are not reached because the Start() method of another enemy's EnemyAnimation begins and is read. Where could the origin of the problem ?