Question regarding AI-controlled sovereigns (likely an easy one)

Is there a way to forbid/restrict specific rival sovereigns (custom-made) from automatically equipping new armor while playing?  I don't care if it's restricting the sovereigns from equipping individual body parts, or if there is a way to code specific computer-controlled sovereigns from equipping new armor at any point in the game all together.

I ask this because some custom sovereigns I've made were designed to look a very specific way during sovereign-creation, and when they're constantly equipping that brown, dull-looking 'styrofoam armor' (that obviously is going to look utterly ridiculous on them), it's become a big annoyance.  I'd expect there is a way to restrict the AI from doing this somehow.

I'll take any solution I can get.  Thank you.