The second move was for each manager to refine the joint list of issues. The third move was for each manager to agree to work on resolving those issues with her. One step at a time, each move within his immediate limit. It's tempting in a dispute to try to come up with the brilliant answer that will settle the whole problem all at once. There are smaller steps required before you reach that point.
Persuasion is like courtship.
You've got to lead the person one step at a time. Proceeding incrementally is the fastest way to get what you want. The slowest way is to push for too much at once. That's when the other person gets defensive, locks up and refuses to budge. But if each move you invite them to make is easy for them, you'll make progress quickly.