For what it's worth, this is how we have built our model. When the game starts, the first available starting technologies provide big defensive and entrenchment bonuses. Later, technologies and assault tactics become available which increase the unit's 'assault' stat. This stat is subtracted from the defenders entrenchment value before combat calculations, so effectively negates entrenchment bonuses.
This ensures that the start and end of the war in the west are mobile, with the main years of the war being heavily skewed in favour of the defender.
The eastern front stays more mobile throughout the war, but still follows a similar pattern. It just never gets quite a static as the west, simply because you have more room for manoeuvre (and the Steppe terrain type provides lower entrenchment modifiers than the grassland terrain of western Europe).
You're right in saying that on the large scale of things, any historical advances would be swallowed into a single hex, but if you can accept some level of abstraction, allowing the fronts to move a hex or two here and there allows the game to be a bit more fun, without actually allowing the player to 'break through' and roll up the flanks. Generally, if you opponent can do that, you're about to lose.
Generally, I think the game captures the feel of WWI in this respect, but if you've any sense you won't just take it from me... as I'm on the development team . Strategy Prime's review says:
At this point, I once again must do my best to restrain the history-freak inside me and avoid a long, overly detailed report on the causes that led to WW1; instead, let me just state the main premises of the conflict that got to be known as The Great War and only later as World War 1. In essence, a complex network of military and economical treaties made it seem – on the surface – that nobody with an ounce of common sense would start a war, but eventually, instead to function as the deterrent, the countless treaties merely ensured that many countries got involved in the war without truly wanting it. Oddly enough, everyone involved was pretty much certain that it would be “over by Christmas”. Not only that it wasn’t over within couple of months, it was also far more bloodier and of entirely different nature than any war that was fought to the date. The World War 1 was, to its greatest extent, a war of industry, static defenses, trenches, mustard gas, barbed wire and machine guns mowing down youth of the nations, a horrid conflict where each side was trying to bleed each other white and where casualties without sense or true purpose mounted into hundreds of thousands, even millions of soldiers.
Commander The Great War manages to capture that sensation and presents us with a game where defense almost always has the upper hand.
< Message edited by Myrddraal -- 12/7/2012 4:14:24 PM >