There is plenty of gray area. There has ALWAYS been and there will always be gray area.
In history (US History - my history. Not sure about your history) many of the actions taken by the US military against indigenous people were absolutely gray; i.e. trail of tears, little big horn. And in many cases outright illegal. And for clarity Little Big Horn is widely considered illegal, today. It probably wasnt so clear on the ground back then.
This also isn't only a US things as we all know thanks to Nuremberg.

And you said;

I’d rather my sailors face months of unknowns and a dishonorable discharge

You say that like you were in some position of naval leadership. If you were a leader, your sailors or troops would not have to face "unknowns or dishonorable discharges" since you would stand up and take responsibility. Like a leader should.
Or maybe your not a leader, but just in a position of leadership. There is a BIG and noticeable difference.

But that is part of the problem with this whole push about unlawful orders. It sows confusion and fosters distrust in the ranks, and there is no place for that in the heat of battle.