The issue isn't smarts, it's arrogance and the only way to tame that is to make it clear the impact of their arrogance.

Demonstrate the complexity and its cost and why it isn't smart.

Show why a lack of consistency isn't smart.

Show why adding work that doesn't align with goals isn't smart.

Show, don't tell. Be the change you want to see in the world. Educate. Encourage humbleness