"John" and I founded and used to run a nonprofit. I have been detached from the company but do not desire or plan on having anymore influence in the organization. I have nearly as much influence as John. He stepped down to pursue other activities and handed the torch to "Ross", a former employee/volunteer. Ross doesn't have any ownership over the company. Neither John nor I can force Ross to do anything, although we can remove him (albeit we don't have a valid replacement).
Ross did not do as well a job as John at running and growing the company, and John was bothered by this, since he felt attached to his company and still wanted to help guide its direction. Thus John began to call Ross nearly weekly, but almost all the conversations would frequently turn heated - John wanted things to be run one way, but Ross felt that John shouldn't have an opinion since he doesn't actually do any work for the company anymore and thus is unfairly restricting Ross's autonomy. Because of these heated calls, Ross now thinks of John as a controlling "jerk" (his word) and John thinks of Ross as irrational and choleric.
Both sides have a point - John doesn't do much work for the company anymore, and Ross hasn't done as well a job as John. I serve as a neutral intermediary between the two, trying to resolve this conflict.
Yes, there is an unclear power dynamic: John wants to act like Ross's manager (and his advice may help Ross), although Ross doesn't like this because he feels like John is bossing her around when Ross is the leader and John doesn't do any work for the company. We considered creating a board but there was the issue of finding board members that both leaders would agree upon.
Both parties reached out to me separately to talk about the issue given that I have the same power as John but don't use it. I wanted to help them resolve this conflict because I saw them struggling and saw room for improvement.
The issue is that a good chunk of John's points to Ross are valid, so I would love for Ross to consider them. However, based on my conversations with him, John feels that his ideas are the best and Ross should be listening to all of them, and thus attempts to impose his will upon Ross and the company, angering Ross. Having more people involved in the discussions may provide a way for John's ideas to be backed by others and show Ross that they are valid, while also filtering John's bad ideas. I am close to both parties so with enough talking I could get them to agree to whatever new systems we implement.
Given their positions of power and hostile relationship, how can John give advice to Ross on issues that both plague that company on a week-to-week and strategic basis without Ross reacting negatively? Or to generalize it for future readers, how can a former leader who wants and thinks they have the same amount of power as the current leader effectively advise the current leader without appearing overbearing?