JAG training is great for lawyers. They are generally more able than other lawyers without that training and experience.
On criminal matters, they prosecute under the Uniform Code of Military Justice, not the statutes they will see in DC.
They also try in front of military judges and tribunals, not civilian juries.
But they are military, they improvise.
I think this is a solid move.
Also, importantly they start getting trial experience at a very young age. Like all military officers you get tested with more responsibility than you can possibly imagine handling at a young age. You learn to handle it. You know like bing in charge of driving a nuclear submarine or flying a several hundred million dollar jet aircraft at age 24 or leading a platoon in combat.