Wouldn't the western front be rather boring? I mean breakouts required advancements in tech by 1917-18 when the mobile offensives really began. The game would be quite dull for UK, France , Germany in 1915-17 apart from fringe conflicts in the middle east. Of course the Germans could have fun in the East against the slowly collapsing Russians.
Austria-Hungary slowly collapsed 'like a flan in a cupboard' and the USA turned up late.