In my opinion, the three scripts I’ve read so far are many times more amazing than the first one in terms of their scope. He did a lot of the heavy lifting in the first movie, establishing the family and the relationships and the world, and now he really gets to play.
All movies are potentially shooting back-to-back, you really need the script dialed in. Cameron is a brilliant filmmaker and all of his projects are masterpieces. Check any of his behind the scenes footage and you will see how much he pays attention to detail.