How can I change the capsule size of the Custom NPC type?

I want to make an NPC that has a smaller capsule and a custom collision, the physics asset collision only works with the wildlife NPC type (this is for regular player collision, it works with guns with any type of NPC).

For the custom collision with the player there is a work around using another Prop as the physical collision in the world. But, the custom and Guard NPC generate a capsule that extends above my custom character’s hit box. I just need a way to reduce either the Guard or the Custom NPC capsule.