We keep hearing that the AFL Coach is really a Manager of people and the public face of the FD.
He has fitness people, medical people, recruiting people, list management people and assistant coaches, working with him to achieve the optimum result for his club.
The tactics seem to come from others, be it the Assistant Coaches, the Tactical Coach or group think.
Even if a side is losing, the Coach could be going ok, but at the same time his assistants might not be.
Therefore, it is fully understandable, that a club could be happy with its Coach, but be unhappy with his Assistants and require changes in that group.