I don’t believe Campbell would take issue with your assessment, given this statement of his:
I’m not a mystic, in that I don’t practice any austerities, and I’ve never had a mystical experience. So I’m not a mystic. I’m a scholar, and that’s all.
I remember when Alan Watts one time asked me, ‘Joe, what yoga do you practice?’ I said, ‘I underline sentences.’ And that’s all I’m doing. My discipline is taking heavy notes and correlating everything I read with everything else I’ve read. I have nine drawers full of notes, and I have four more packed down in the cellar that I can’t get another piece of paper in. For 40 years I’ve taken notes on these materials that seemed to me to be opening the picture to my mind.”
(from an interview with Jeffrey Mishlove)