I believe that DJT's best course of action is to carefully look into the issue, and if warranted, issue a pardon before there is any further legal action.
There are many reasons, some being the interest of justice, and some being that it would get all of our troups on his side.
Yes,unless I'm mistaken he has the power to "pardon" a member of the Armed Forces before a court martial has begun and while one is in progress.I've read that the worst thing a President can do is to simply comment on a particular military criminal issue...which,under the UCMJ,can be seen as "undue command influence".Such an act can,as I understand it,work against the accused.