Yes, but then all map hexes would have to be level, open terrain. The armies would have to be deployed symmetrically on both sides of the map. The barometric pressure and weather at both of the players locations would also need be kept the same throughout the game, just to be sure that one player did not derive a decisive psychological advantage due to sunny conditions as opposed to depressing, grey clouds. I think this almost goes without saying.
No, seriously, I think the best way to prevent whining, or at the very least render it moot, is to mirror match the battle under the same rules. It he defeats you in the first battle, it is obviously because the scenario is hideously unbalanced. When he soundly trounces you again in the mirror match, you might actually consider giving your opponent some credit for, just possibly, actually being the better player.

When I played Colin Knox in Austerlitz, I insisted that he play the Coalition since I believed the French had the advantage in the scenario. He honorably agreed to do so, although I am sure his uniform chaffed throughout the battle. Nevertheless, he defeated me. He is the better player and I readily admit it (although the sun was in my eyes, my cat ran across the keyboard during a critical move, my wife was talking which distracted me from the game, etc, etc, etc.).
If you think the battle was unbalanced, and your opponent refuses to play a mirror match with the same optional rules then yes, you were probably duped in the negotiation phase. If your opponent agrees to the mirror match, and defeats you again, set aside your personal pride and give him the credit he deserves. I guarantee that you will be a better person for it.
