I guess the answer depends on what your reasons are for choosing a 1916 set-up. Are you choosing it because you’re trying to replicate the situation that existed in 1916, for reasons of historical interest? If so, having contested territories is probably the way to go, since it would be authentic to do so. Or are you choosing it because it introduces variety into the game, meaning that it gives you a different starting point than the 1914 one of the official game? If so, then you should probably avoid having contested territories because, as you said, they players won’t have much choice about where to fight.
Keep in mind that, as Barbara Tuchman noted it in her book The Zimmerman Telegram, many generals as late as 1917 still weren’t questioning their basic approach to waging war in a trench warfare environment. As she put it, their thinking was still focussed on where along the front they should butt their heads next, not on whether they should do it or on questioning their fundamental concepts of how they should do it. That eventually changed with such innovations as the development of infiltration tactics on the German side and the mass use of tanks on the Allied side – but in 1916, generals still thought primarily in terms of huge, long, grinding and virtually static battles of attrition at specific points along the Western front. In a sense, it was the entire front that was “contested”, and it was along its whole length that the two sides were locked; it’s simply that some specific points of it were, at various times, contested at an exceptionally high level of intensity.
In some respects, it even didn’t matter very much whether these huge battles took place at Point X of the front rather than at Point Y, since one stretch of shell-blasted mud looks pretty much like any other one…at least from an objective point of view. Subjectively, however, some of those stretches did have symbolic value, which is precisely why they were targeted for attack or defended so tenaciously. For example, I think that the Ypres sector was a small segment that Belgian soil that the Allies managed to hold throughout the war, and that as such it was considered highly symbolic. Similarly, Verdun was targetted by Germany in part because it had historic importance and therefore was seen as an area that France was “bound to defend” with everything it had, which was precisely what Germany hoped because they conceived of the Verdun offensive as a means of “bleeding France white.” So in deciding how much latitude you want to give players about where they can choose to fight on the game board, you may want to consider what factors might make a difference (and how much of a difference) in their minds about whether they’d like to fight here rather than there.
