One lesson I learned from data modeling is whether you are modeling entities or attributes, they only have one definition.
I have generalized that to each thing only has one master.
In terms of responsibility, there should only be one person that has ultimate responsibility, or the responsibility gets muddled.
In terms of defining a tool, the tool should have one purpose or the effectiveness of the tool suffers. Yes, I know there are multi-tools, but the purpose of multi-tools is to have a range of tools in case of emergency. I don’t know any multi-tool that is better than a single tool for one task.
More than one master results in a compromise that lessens what each master receives.
Reporting to two bosses either means more work or compromising so that each boss gets what they need.
Designing for different uses typically does not work. That is why we don’t have cars that are also boats or forks that are also knives. Both of these have been tried but never worked.
When you are designing, whether that is products, or organizations, or creative pursuits, always look to see who the masters are and how you can pick one master going forward.