Sometimes generals had an easier job to get "hyped". If the defense is much stronger than the attack it is difficult to achieve spectacular successes. During great parts of WW I just the means to beat the enemy did not exist. Even Napoleon would have had problems in this war.

Rommel (my favorite for being overrated) was a good general. But he was not the super hero as whom he sometimes appeared. You don't have to be bad to be overrated, just not so good as many thought. Rommels ruthless first attack on Tobruk f.e. was a shameful desaster. More than once the other generals had to save the situation, f.e. in the battles in late 1941 when Rommel sometimes lost even contact with his divisions because of imprudent trips. The high command thought of him more as an adventurer und would have preferred to get rid of him but he was Hitlers darling and too well known in the public already.

Macilrille, it's interesting that you speak of Fall Gelb, a candidate for the most overrated victory imho. The success of Fall Gelb was a matter of coincidence, luck, disobedience of some energetic excellent lower generals combined with some (but only a little bit) incompetence of the allied command. The Germans never used blitzkrieg strategy deliberately with success, instead they stumbled into it. If Fall Gelb would have been conducted as planned the forces of France, GB, Belgium and the Netherlands would have performed much better than they did. The blitzkrieg was however a comfortable concept for both sides, the Germans could dupe themselves that they were the best fighters with a superiour tactic (which led to the desaster in the east a year later), the allies could excuse themselves why they were beaten although they had had far stronger forces.