I’d say less than 10%. He thinks all life was created in a few days around 6000 years ago and almost all rocks were laid down during the worldwide Flood. You may agree on the age of the universe and of earth, and you may agree that God had something to do with all that stuff. Is that substantial agreement? I suppose it serves your purpose to minimize the differences and emphasize points of agreement, but really there’s slim pickings to be had in that regard.