When it comes to the movers and shakers in the Marine Corps, they virtually all will visit the same event this week: the Marine Corps Sergeants Major Symposium in National Harbor, Md. An annual gathering of the service’s most senior enlisted advisers, the symposium frequently leads to recommendations that affect change in the service. Led by Sergeant Major of the Marine Corps Carlton Kent, it traditionally pushes up a handful of suggestion to the commandant each year. Many of those have made their way into Marine Corps policy in recent years, including a crackdown on body-fat standards, the approval of campaign…