No, the president can tell the DEA to do their job, which is studying whether they should deschedule cannabis. He can’t tell them what results their job should have.
In this metaphor, the general can tell the private to go fight on the battlefield. The general cannot determine whether the private kills people or comes back alive. The general can train the private and give the private all the support and tools necessary to win a fight, but in the end the results come down to the private.