Answer:
Automatically created load combinations are generated solely from the definition of combination expressions. Thus, it may happen that two load combinations are created according to different combination expressions, but contain the same load cases with the same factors.
However, the load combinations only seem to be the same; the information saved in the load combination is different. Thus, the load combinations include an assignment to the underlying combination expression and can subsequently be selected collectively; for example, during design.
Since it is thus necessary to define a unique combination expression for each load combination, the load combinations that are apparently the same are not combined.