“standard NRA firearms training course”?
Are you saying that a Military firearms training course would not be acceptable?
It might. Two issues though:
1) The military course probably does not have a section on legal rules for use of deadly force in a civilian/on-base setting, and more importantly
2) An NRA course can be gotten through off-base on the person's own time, using any NRA-certified instructor. That prevents a CO from stopping concealed carry through simply not scheduling any military pistol courses, or limiting enrollment.