In her thoughtful and insightful article on UX Principals for Better Content, Lucia Z. Wang, discusses content personas as being different (slightly) from marketing personas. This is something we fundamentally disagree with, like a project brief, customers need one holistic persona that captures all their facets without this there can be no alignment between experience, product and marketing.
We use the analogy of a architect building a house (the software developer) but then the landscape designer (the media planner) building the path to the front door on the side of the house. Because they have fundamentally different specs. Ideally the personas capture each type of customer from 360 degrees, because the their needs can differ by time of day, role during the day, etc. It is a blending of not just one use case but of media insights and data points as well as geographic and behavioral information. Even if the persona isn't granular, it at least needs to address all the different stakeholders creating the experience.
So all the creation stakeholders, including of course the client, need to align with the persona before anyone starts pouring the house's foundation.