The Long answer that most Marine aviators were usually assigned to a squadron. The Letters in front of the the numbers changed from time to time based on the squadron's function, usually bombers, Fighters or Pursuit. They also had some torpedo squadrons also (I think)
Anyway, I believe those designators are the Units called for in the template.
But there were overall Marine air groups, who, when embarked on an aircraft carrier fell under the Navy embarked Air Wing, with all sorts of Task Force/Group and Fleet numbers.
Tracking the squadrons and ships involved is easy, the Task forces changed almost daily, and depended on where the ships were at any given time. Have fun