The Commander in Chief can discharge anyone in the army for reasons such as "unsuitability". But the President can only appoint Generals with the advice and consent of the Senate. By law, he can only appoint suitably qualified candidates (ie serving senior military officers) except at a time of war. This makes it difficult for the President to simply fire all the Generals and put "yes-men" in their places.

Perhaps it is worth noting that the military oath is to the constitution, not to the President. Soldiers swear to obey the commands of the President "according to the regulations". So illegal or unconstitutional commands do not have to be obeyed.

The Commander in Chief can discharge anyone in the army for reasons such as "unsuitability". But the President can only appoint Generals with the advice and consent of the Senate. By law, he can only appoint suitably qualified candidates (ie serving senior military officers) except at a time of war. This makes it difficult for the President to simply fire all the Generals and put "yes-men" in their places.

Perhaps it is worth noting that the military oath is to the constitution, not to the President. Soldiers swear to obey the commands of the President "according to the regulations". So illegal or unconstitutional commands are still illegal and must not be obeyed.