Being “brutish” (stupid NASB) (1198) is different than not having “understanding” (998). For the moment lets assume that ignorance is the same as stupidity. It isn’t, but often looks the same and can produce the same results. Think of how we are told to be like children. Here is one reference.
(Matthew 18:3 KJV) And said, Verily I say unto you, Except ye be converted, and become as little children, ye shall not enter into the kingdom of heaven.When it comes to knowledge and experience a child is lacking. They are ignorant. It can even seem to be stupidity. They are naive and often trusting when they should not be.
But a child can understand. They can know when they have been had even if they don’t know how.
This is part of the reason we talk about the heart as well as the mind. Our popular terminology is that Jesus comes into our hearts. We also talk about transformed minds, but it starts in the heart.
So? You can have enough understanding to be pleasing in God’s eye at any level of knowledge. You don’t need to have hundreds of verses memorized and a college degree in theology to live an obedient life. Go with what you have.