Rommel apparently wasn't the best tactician since Alexander. Monty fooled the hell out of him in North Africa fairly easily...if a conceited Brit w/ a Frenchie hat could beat him them he is certainly not the best tactician since Alexander. Also, he was responsible for the defenses along the Atlantic Wall...we see how well those worked out for the Nazis!
you apparently don't know this, but the Atlantic Wall wasn't completely finished on D-Day.