How do i use the same animation for different arm positions?

Hello, i’m a bit of a novice when it comes to animation graph. I have a character that has 3 different arm positions:

  • Holding a heavy weapon with 2 arms
  • Holding a pistol with one arm and the other arm is supporting
  • Not holding any weapons

For the first 2 positions i have the aim offset working. I have a lean animation and i want to use it with the 3 different arm positions without creating 3 different lean animations. I know i have Layered blend per bone, but i want to reproduce everything from the lean animation except the arms, so i can’t use that because the arms belong to the torso hierarchy. How can i achieve this? Thank you.