If you're looking to convey a sense of someone being naive or making a foolish decision, you could use phrases like:
* Ɔwɔ ɔyɛɛ adeɛ a ɛnyɛ papa (They did something bad/foolish)
* Ɔno nni nhumu (They lack wisdom)
* Ɔno yɛ akwadaa (They are naive/simple)
It's always best to choose your words carefully and avoid using insulting language. If you want to express your opinion about someone's actions, it's better to focus on the behavior itself rather than attacking their intelligence.
Remember, respectful communication is key in any language!