So there are a few things to untangle here and we will take them one at a time.

First is that Both numbers youve heard are broadly accurate, they are just for different things. The 60k(really 58K or so) is for the number of dead from all branches during operations in Vietnam and surrounding nations. Thats why there are as of now 58,320 names inscribed on the Vietnam Veterans Memorial in DC for instance.

The 200k number is when you add in the 150k or so wounded who required some form of hospital care but who did not then die from their wounds, or did so at a point or in a way that would not more them to another category. A roughly equal number is also in the category of those who suffered a minor wound but did not require any more serious care in a medical facility.

As for the breakdown by branch the US Army had a total of 38,000 deaths from enemy action or non combat accidents, self inflicted, etc, and 97,000 wounded. The US Marine Corps had about 15,000 dead and 51,000 wounded. With the Navy, Air Force, and Coast Guard rounding out the rest.

As for actually presence, you would be correct in saying that the total American presence was far more of an Army show vs a Marine run effort. Restricting ourselves just to South Vietnam itself a total of about 1.7 million members of the Army served in country compared to about 390,000 Marines. Additionally the US presence in Vietnam was organized around pairing US Corps level commands with the geographic based ARVN Corps commands. Thus the USMC presence was mostly concentrated in and around 1 Corps/1st Military Region which was the northernmost and bordered the DMZ and North Vietnam. The USMC effort was under the III Marine Expeditionary Force and the 1st and 3rd Marine Divisions, they were also paired with the US Army's XXIV Corps which contained most of or all at different times the Americal Division, 1st Cavalry, and 101st Airborne.

Now certainly the USMC presence in country participated in many of the most famous actions and more intense fighting, Khe Sahn, Leatherneck Square, and the city of Hue all fell within the region the Marines were assigned. And their casualty figures certainly bear this out as well.

But they were never more than a minority of the total US presence in the war, despite popular media and films like Full Metal Jacket or Born on the Fourth of July which do focus depict members of the USMC. Though certainly there is far from a shortage of ones that depict soldiers(and sailors or airmen) as well.

For a deeper dive you may be interested in this. It is a demographic breakdown of US military casualties by conflict prepared by the Congressional Research Service. https://fas.org/sgp/crs/natsec/RL32492.pdf