In USE, air force and navy are largely abstracted but this is also a good point because reduces the total number of counters on the map. The “sorties” system may look strange at first glance because they are not losses in naval or air battles. However, the “losses” are implicitly taken into account in the fatigue of the units by doing these operations or sorties.
Again, we can think in terms of real-world battles. One air force squadron or wing suffers many different sources of losses during war period. Combat losses, operational losses due to bad weather, lack of replacements, malfunctions of engines, lack of trained pilots etc. If one squadron does not participate in many missions, the probability to the ready for combat (at least in terms of material) is higher than in the case that a unit that is flying everyday. So I think this is the correct interpretation of the air and navy combat system.
Of course, in the same way that I proposed a new system with corps for ground units in my previous entry, we could think on adding new sub-units for squadrons inside a large wing structure. This is done is an expansion of Totaler Krieg , which I plan to review in a near future too. But I feel that for USE the current system could be the appropriate one for Air and Naval areas.