In the Marine Corps, all heavy helicopters are deployed within the Landing Fleet, precisely speaking, under the jurisdiction of the Fleet. They are usually stationed at the Naval Air Station and operate with the Landing Fleet and carrier battle group during wartime. When necessary, they are assigned to combat units to participate in operations.
As for the Army, management isn't as strict.
Typically, within the assault air force or transport air brigade of the main divisions, there is a battalion equipped with heavy helicopters, generally numbering between 20 and 30 aircraft. Within the battle zone's direct air brigade, there are usually 2 such battalions, with the total number of heavy helicopters not less than 50.
Simply put, there are at least 200 heavy helicopters in one battle zone.
The key is that the battle zone headquarters can allocate these heavy transport air battalions as needed, such as concentrating deployment in a specific direction.
