You can't cut an enemy supply line if by so doing you put yourself out of supply. Two expansion sets for logistics are promised. Introducing HQs into the mix would change that atmosphere, which I think might rob Victory of some of its charm. I'll have to play several times before I can be sure, though. Fifty mile hexes.
Ground units are corps, steps are divisions.
Air units are wings, each step is 100 planes. Air units can react two hexes after the bad guys move. Combat is between units in the same hex. Units throw dice equal to their steps in combat, but hit on different numbers depending on their ratings for ground, air, or naval combat. Units also have different movement rates.