How about merge the two mod into one and taking it a step further?
For example, when a character has the "Cowardly" trait, the trait is removed after a certain number of zombies are killed, then gain "Brave" trait after a certain number of zombies are killed, and finally the "Desensitized" trait.

You can do this by combining the 2 mods, currently.

Set Become Brave limits to: 350-1500
Set Become Desensitised limits to: 2000-5000

First you get brave, then if you continue to cause more violence, you'll have a chance to become desensitised.

Also this mod removes mutually exclusive traits, such as cowardly when you get Brave. It's just that being a coward, decreases your chance of getting Brave.

I think the lucky and unlucky traits would be a nice adition to the pool of traits that modify the chances of geting brave or desensitized