Eventually, you and your clients will release the project to a director, photographer, editor, illustrator, etc. At that point, you must say to that person: “Go make your art.” That’s what you’ve hired the person to do. He’s an expert at the craft. You’ve selected him from thousands of other people. Now, let him make something wonderful.
If you have the right person, let him go. If you don’t have the right person, stop right now and find someone else. The risk now isn’t that something will screw up. It’s that you’ll fail to get what might have been magic from the person you thought could give it to you.