Okay, so I have lost one game, am losing another and the third is questionable, but I still enjoy this game because...
GOA and the principles of war
From Clausewitz, there are nine principles of war and playing GOA without adhering to those principles is likely to result in failure:
Objective – Set your sights on some achievable objective and allocate your forces to do that. It could be (for TE) to capture German food hexes in and near East Prussia or, for the CP, to destroy French or Russian industrial production.
Offensive – Seize and retain the initiative. Although offensives are expensive, you cannot win by staying on the defensive.
Mass – Overwhelm the enemy. ‘Nough said.
Maneuver – Maneuvering can be difficult in GOA, given the slow, one hex movement. Strategic movement is faster, but can be stopped by attacks on the destination hex. Still, you can move your forces around, rather than through, the opposing force and gain an advantage, particularly if the move cuts the opponent off from supply. Against AI, I have managed a double envelopment. I could have done that against my human opponents, if they were not as bright as they are.
Surprise – Attack the enemy where he is weak and when he does not expect an attack. I surprised an opponent with amphibious attacks on unguarded ports. He did the same to me. The next game, I took care to guard the ports. I assume he did the same.
Security – See “Surprise.” Do not let the enemy do that to you.
Economy of force – Guard your self with only the minimum forces needed. Cavalry can fill this role, but if you have a valuable place that can be attacked, then infantry will be needed.
Simplicity – Plans are ruined by the first shots in battle. The more you depend upon units moving to replace units that follow those attacking the enemy, the more you added to the complexity of the plan and the likelihood of something going wrong (like an enemy attack on the third unit, freezing it in place and leaving one and two isolated, out of supply and likely to go away).
Unity of command – It is a given, with one player on each side, that there will be unity of command for everything. A multiplayer game would change that, particularly if the different players were rewarded based upon national objectives (i.e., the British were more interested in keeping the BEF intact than fighting the Germans in the first couple of months of the war and the French could do nothing about it).
As a note to the comment about unity of command, a multi-player game is possible even without revisions. Say three players take the TE side (French, British and Russian&Serb -- keep the Slavs together) vs two CP players (Germany, Austria + Turkey + Bulgaria). Each individual player orchestrates his/her forces and economy with some regard for the objective of winning the war.