In the strategic way I think the Maginot line was the worst of it all. The French put all of their defence ideology and strength in it, yet the weakness was the possibility to attack around it and they knew it, and yet they did nothing to stop it. Then again if the Germans had attacked in late autumn 1939 or had used the original attack plan in spring 1940, the Maginot line might have proved its stregth (?).

On the German system in 1944 I think it was not possible to use the railways any more than the allied accepted as they themselves ( The allied ) were dedicated to bombing the railways to kingdom come in Normandy. Putting more reserves in railway systems after spring 1944 other than stopping the bombing would have gone like smoke in the wind ,I think. So it was not possible to make the troops move any faster, yet the major mistake was in keeping the 15th Army stay in Calais until the invasion truly was succesfull, but then again we must remember that the allied succeeded in faking Hitler to believe there was another invasion on its way.

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