Robert, not sure about the term “Track Acres.” Though perhaps it is referring to the acres of a specific TRACT within a Unit. When a Unit is created, separate pieces of it are designated as individual tracts. These tracts will often be of different sizes (i.e., surface acres, such as your 40 acre & 80 acres), and typically each tract is allocated with a different percentage on the oil & gas produced (the Tracts “Participation Factors”).
The division of the Unit into Tracts, the Tract sizes, and their various Participation Factors, is spelled out in the “Unit Operating Agreement” which was generated when the Unit is created. Although in your example one is twice the surface size of the other, you’d need to refer to the Unit Operating Agreement to determine which has a larger share of the Unit’s production. It’s possible the smaller one is allocated a higher percentage of the Unit’s production. Hope this helps.