How have you dealt with possible overlaps between Product Managers, Business Owners and Marketing?

Ah yes, I remember this article :) I think the key point Marty makes is "Things go wrong when these two roles are not clearly defined." There are two aspects of "defined" to work out here. From a management and org structure perspective, there needs to be definition of who is accountable for what and how these roles should work with each other written down somewhere to serve as a starting point. The next level of definition occurs between the matrixed individuals when you look at these management definitions and define your own working agreements that help you both succeed in the context of the shared portfolio of work, your individual strengths, and all the undocumented expectations that you discover along the way.

The uncomfortable truth is that you can't just produce a RACI and expect everything to work out fine. This is because RACIs try to separate out work under the idea to make things clear and clean, but product work is highly collaborative which creates the conditions to blur the lines.

My best advice here would be to think about what makes a Product Trio/Triad successful, and apply that same mindset to your matrixed partners:

1. Have shared OKRs

2. Work together (collaborate) vs. create handoffs (coordinate)

3. Align early on your decision making process

4. Create the conditions where its ok to have conflict and mechanisms to resolve it