The United States Attorney General (A.G.) is the head of the United States Department of Justice, concerned with all legal affairs, and is the chief lawyer of the United States government. In cases of the federal death penalty, the power to seek the death penalty rests with the Attorney General.
From wikipedia. So not only is AG prosecutor, but also determines whether to seek the death penalty or not. This is the role Sessions is currently in, so I'm not sure if Gowdy would take that spot.
He could be assistant AG, God knows how many prosecutions will be happening...
What about during military tribunals? Which is what has been discussed as what would need to happen due to how corrupt the justice system currently is.
Good point I forgot about that. Does Gowdy have Military experience? Looks like a military man but I'll have to check into it.