The correct answer to this open question is the following.
Unfortunately, you did not include the hypothetical scenarios, so we do not have that reference. However, doing some research we can say that one hypothetical scenario would be the following.
The President issues an order that women in the armed forces may now serve in direct combat capacity during wartime.
If this is the case, then we can comment on the following.
According to the formal powers of the president outlined in Article II of the Constitution, the President of the United States is the Commander-in-Chief of the Armed Forces: Army, Navy, Airforce, and Coast Guard. So the President has the power to issue orders in this regard.
This act is constitutional because it is included in the above-mentioned section of the COnstitution of the United States. As the Commander-in-Chief he is, he can order whatever he considers is necessary for the security of the nation and for the most benefit of the troops.
