I don’t think I understand.
(ICH E6 4.1.5 and RECOMMENDATION ON THE CONTENT OF THE TRIAL MASTER FILE AND ARCHIVING July 2006 3.2.24 footnote 9) It is the Investigator (or if a team is involved, the Principle Investigator) who has to maintain a list of those delegated significant trail related duties!
The I/PIs are required to perform all tasks themselves, unless they delegate tasks (& document PI oversight) to appropriate team personnel, who are documented as being qualified by education, training and experience, to carry out those tasks. Surely only the PI can approve the delegation of a trial related task?

Not to be confused with (ICH E6 8.3.24) the signature log used to document signatures and initials of all persons authorised to make entries and/or corrections on CRFs. Obviously (8.1) it is acceptable to combine documents provide that the individual elements are readily identifiable.