More than just trust however, ambiguous work requires a specific kind of energy. Consulting is about changing clients. You’re often an outsider, brought in to catalyze some kind of change that the client has been unable to change on their own.
The problem with a carefully crafted positioning is that it typically makes the wrong part efficient - it makes it easier for clients to hire you for well defined work. It allows greater legibility, trust and expertise around work which is well defined.
This kind of taste is hard to signal with a positioning statement. To develop this trust in someone without actively working with them before requires a strong understanding of the person’s point of view and vibe, which is why sharing your point of view in depth matters.