Churchill as a sponsor of special forces

Did Churchill champion the SAS and SOE even though they were not directly his ideas?

Yes; he backed those organisations, along with the SBS and other special forces, even though he was not their originator.

Churchill did not originate the SAS or SOE. He supported and championed both organisations. The same political sponsorship extended to the SBS and a wider range of special forces. Detailed institutional histories are left outside this short exchange, but the distinction between founding an organisation and backing it remains clear.