They looked at the externals but did not ask of the Lord. There is nothing wrong with collecting the facts. God does not celebrate ignorance. The point is that in all our ways we are to lean not on our own understanding but to acknowledge him. Note that Proverbs does not say we are not to use our own understanding, just don't rely on it.
Godly wisdom based on scripture is the most important way.
He also uses impressions. Impression are impressions. Don't ignore them, they may be of God. But they are not gospel, don't bank your salvation on them. They are like a radio signal coming in on a static-filled line.