Thomas Sandgaard says that dissatisfaction with the style of play encouraged by Johnnie Jackson led to his removal as manager. He would have preferred to see players pressing higher up the pitch: https://www.standard.co.uk/sport/football/thomas-sandgaard-charlton-johnnie-jackson-sacked-b997705.html
Of course, leads to questions about whether Sandgaard wants to be the manager himself and this was raised in the interview which drew a denial.
As bad as the satirised 'fan manager' would be an owner-manager. Sandgaard needs to make a high quality appointment and then let them get on with the job. Setting targets is one thing, it happens in many walks of life, but is up to the manager how those targets are achieved.