If we are discussing an internal auditor, then it may be O.K. It's not necessary that the lead auditor be an expert in all these standards, as long as there's someone who has competency in each of the specifics of, say, 13485.
If we are speaking of an external auditor (may be a CB auditor) then it's possible that they have competency in all standards. In my experience, the lead auditor doesn't have to be an expert in all, since they may have someone who is more experienced in one of the standards.
I'm interested to know what type of organization has both ISO/TS 16949 certification and ISO 13485?