There was precious little manoeuvring, mostly just slaughter, years and years of slaughter.
True but it is not mindless slaughter and that's a feature, not a bug. One of the problems with Commander:The Great War and To End All Wars is that the hex scale is so big that unit densities impose an essentially artificial stalemate and while this may apply to a certain extent on the Western Front and Italy, it is less reasonable in the East, the Balkans, Africa and Mesopotamia and Palestine if the Ottoman Empire is with the Central Powers. In those extraneous theatres, mobility remained a major factor throughout the conflict and WW1G although they are unlikely to be decisive in and of themselves, they can have a nasty impact on National Will (NW). Another is that they are adoptions of game engines that were never intended to recreate the First World War and in general, the fit is pretty sloppy.
Barring an unlikely (but possible) victory in 1914, in WW1G everything is tied to National Will and politics, finite resources that must be carefully managed if you are to avoid collapse. In one of my games, England's NW took a big hit in 1917 from a failed Grand Offensive, a special type of mandatory theatre attack where success can improve NW, even at the cost of heavy casualties but failure can be debilitating. In this case Britain's cumulative NM loss due to Irish rebellion, worker's strikes, casualties and combat failure were compounded by an exceptionally effective unrestricted U-Boat roll that plunged the country into revolution. The U-Boat threat affects NW and the economy and can only be countered by building and deploying escorts and advancing technology. Eventually a Communist Britain left the war in the January 1918 turn. This is a rather unlikely outcome even in WW1G but one that is plausible and probably not available in the other titles. Recall that KGV refused asylum to Cousin Niki because of fear of what the increasingly socialist English workers might do if he should shelter the autocratic ex-Tsar.
WW1G is a computer port-over of an incredibly complex board game and uses its own unique engine, not the AGEOD 2.0 engine used by To End All Wars, which is a remarkably poor fit for the subject. In WW1G each nation, major and minor have their own unique NW, economy and manpower resources whereas these are allocated by faction in TEAW. To be clear there are still has many issues in WW1G but in my opinion, none of the other titles even come close to reproducing the strategic considerations of the conflict as well as this game does, which befit its board game pedigree.