It helps to substitute "war economy" with "full mobilization" of the war effort in Germany itself. That includes measures like mandatory employment for German women and the broadening of rationing as Speer directed what had been protected resources to keeping up arms production.

An ongoing, related question is why did the Allied bombing effort end up being so diffused as to targets and tactics? The Air Forces bitterly resisted the tactical use of bomb resources to attack French transportation infrastructure until Eisenhower threatened to quit in the build up to Overlord. Also, the industrial targets used in manufacturing were easy for the Germans to disperse. The one campaign that truly was hurting the Axis was against her oil production. I've read some felt had it been more of an overall priority Germany could not have fielded armies even with synthetic replacements in POL.