Right this is usually how it works, and if said consultancy saves the day then the existing management at the company assumes that that consultancy walks on wat

Right this is usually how it works, and if said consultancy saves the day then the existing management at the company assumes that that consultancy walks on water and keeps shelling out money for the perception that problems will not arise. If they do the process is repeated. What consultancies are selling is an illusion, an illusion that management is willing to pay for so long as the perception is that all is well.