By avoiding the offensives of Plan 17 then French concede all the initiative to the Germans, virtually admitting they cannot fight them on equal terms. I don't think this is realistic given how slim the German advantages over the French were: better rifles, more machineguns, minenwerfer and howitzers, all of which were not shown to be superior to the French arms and doctrine until the clashes of 1914. I personally don't think the big French-German army battles offer much scope for a quick Entente victory. However they are totally necessary so other events can happen which are more likely to bring about a quicker Entente victory, without them the Germans are free to go nuts.
By going ahead with Plan XVII even after they knew the Germans are attacking in Belgium, the French very nearly fell into the trap that was intended by the sicklestroke. That they were able to reverse course and redeploy in such a short time in late August is almost miraculous, but their blinkered "war means attack" mentality nearly cost them the war.