I recommend both these books to pastors, and particularly to Regional Pastors. They can provide a lens and language that could generate vital conversations in one-to-one or group conversations with pastors.
Regional Pastors Bookshelf - The Coaching Habit: Say Less, Ask More & Change the Way You Lead Forever
This relatively recent book is officially about 225 pages but it reads like something half that long. I found it compelling and believe it may have real value for the ways in which Regional Pastors interact with other pastors.
If you are looking for a book around which to gather local clergy to have good conversation on transitions, The Second Mountain is an approachable and compelling read.