I'm not sure I agree with the assessment on France. I might be mistaken, but I was under the impression they had a reasonable strategy for regrouping after the Nazis decided to give up on going through the Maginot line. The issue was that they misjudged the pace at which the Nazis would make it through the Ardennes. And if I'm not mistaken, the reason for that misjudgement was they didn't expect that amphetamine fueled soldiers would be able to work the hours they did.
I think the battle of France kind of came down to luck on the timing more than either tactics or the "unstoppable German War machine".