How to transition from one melee attack to another in script

That transition from inward slash to outward slash looks really good in the preview.
I call my attacks with async await like this:

Code (CSharp):

1. async void Slash()
2.     {
3.         _isAttacking = true;
4.         await Task.Delay(4000);
5.         int attackChoice = Random.Range(0, 2);
6.         if (attackChoice == 0)
7.         {
8.             anim.SetTrigger("OutwardSlashTrigger");
9.  
10.         }
11.         else
12.         {
13.             anim.SetTrigger("InwardSlashTrigger");
14.             anim.SetTrigger("ComboTrigger");
15.         }
16.         _isAttacking = false;
17.      
18.     }

That ComboTrigger is the transition from inward to outward but it cuts the inward slash way too short so it's basically a weird looking outward slash.
How do I code it so it's just like in the preview window?