They did, sure, but Germany didn't exactly have a solid plan for when that didn't work because you weren't fighting a nation a fraction of your size. They stomped Poland, the Netherlands, Belgium, Luxembourg, Denmark and Norway because they were only a fraction of the power of Germany. Taking over France was a a total fluke that only somehow worked because the French really didn't seem to understand that the Germans were obviously going to take the only war plan with a slim chance of winning. But against any tougher of a foe they didn't have any real chance. They probably could have taken the UK if not for the small detail of "50 miles of water guarded by the most powerful navy on earth vs. your puny joke of a navy", and after they ran out of easy pickings, their entire war plan just ground to a halt because they had less manpower and industrial capabilities than their enemies