3rd person game : Animations : standing, crawling and crouching

Hello, I want to make a 3rd person game, I implemented the Unity asset “Starter Assets: Character Controller”, which is based on character movement, camera tracking and movement animations (running, walking) using a Blend Tree
Only I would like my character to move in a way other than standing, including crawling and crouching with and whitout a gun.
What would be the most suitable way to do this? Make as many Blend Trees as there are ways to move? And each time change the blend tree according to its movement?
Or another way to do it?
Any tutorials video about all that would be great