If you look at this part of the COH2 design, and compare it to the original map designs of COH1 (Yes, Achelous, Lyon, Vire, Scheldt were ALL on the original list of automatch maps) you wold think that Relic designers really believed if only the Germans had held out long enough they would have won in the end.
That seems... uncharitable.
The Allies in Normandy did come to the conclusion that if they fought the Germans on "anything like even numbers", they would lose. And so, as I understand it, the design intent was essentially that if the Axis can survive the Allied Zerg-rush, their individually superior units could or would turn the tide.
After all, it would not be feasible to merely declare that because the Germans lost the war, every German player must lose every game. That would be No Fun (TM). What they have done is determine that style in which the victory is achieved: the allies win by taking early map control and crushing the Germans under weight of numbers (especially viable back when territories gave popcap); the Germans win by holding off the allied assault and then beating them one on one.
This is a particular aesthetic, not a historical interpretation.