I've seen that happen - more as PO (product owner) and PM. In those cases PO owns the 'Why' and 'What', PM owns the 'When' and liaises with EM for the 'Who'; EM

I've seen that happen - more as PO (product owner) and PM. In those cases PO owns the 'Why' and 'What', PM owns the 'When' and liaises with EM for the 'Who'; EM owns the "How".