Early-stage regulated ventures need governance and operating calibre they cannot afford full-time. The two standard answers both fail: hire someone cheaper full-time, and the role's fit-and-proper bar isn't met; hire someone excellent as decoration, and the bar is met on paper while the work goes undone.
Fractional works, but only when the role is engineered for it. Scope the decision rights precisely. Make the information arrive pre-digested, so senior judgment is spent on judgment. Put the cadence on the calendar so presence is structural, not heroic.
Done properly, a fractional senior person is not half a person. It is a whole person applied to a well-designed fraction of the problem, which, at this stage, is the honest shape of the job.