Would Rommel have been as successful against the Allies in North Africa without the Rebecca spy cell operating in Cairo.This cell, and other intelligence sources, gave him the entire allied Order of Battle, as well as Allied intentions in North Africa. He was able to use this information to consistently suprise the Allied commanders, seemingly appearing out of nowhere, and creating the legend of the Desert Fox. It's interesting that at the Battle of El Alemein, he had lost most of his intelligence sources, and had little idea of Allied plans.
At El Alamein Rommel was on the defensive, which was a kind of battle he didn't specialize in; moreover, he had lost all air cover and was greatly outnumbered by the enemy. In such a situation he tended to rely on mines, which he wrongly thought to be a weapon of destruction where it is actually only a weapon of delay. He did so again in Normandy. The spy cell definitely helped him in North Africa but I think the persistent incompetence of the British generals facing him, as well as the nature of the terrain he fought in, also were in his favour.
British and American incompetence. The American military attache in Cairo, Colonel Fellers sent comprehensive daily reports to America on the state of the British in the region. This was in the diplomatic Black Code which the Italians had broken, and all this information was sent on to Rommel. His Horch(radio itteligence) company could also decypher British plans from their radio communications.
I think it was the German intelligence unit working radio messages that gave Rommel decent advantage. They were captured and Rommel Lost his info unit. Otherwise it was known he used the Storch to see frontline Action and unit movements and the armored British vehicle as his HQ which helped him at least once survive joining a British convoy in the desert.
Re. mines: Rommel understood mines and what they can be used for quite well. They are weapons of delay, certainly, and he used them that way against the British and later, American forces in Africa. In fact Eisenhower was very frustrated in there by the sophisticated used of mines by the Germans and Italians. Mines are also used to augment defensive positions. Both sides used them to good effect and I believe there are many millions left in N. Africa. They can be used to channel enemy forces into kill zones, or use them to deny the enemy certain terrain while most of your other assets are concentrated elsewhere. What people don't realize is that to get the most effective use of minefields they have to be covered by fire in order to keep the enemy from quickly removing them. Mines by themselves are only of limited value. In Normandy the minefields were intended to delay so that the Allied forces would only have a very narrow beachhead when the counter attack went in! The idea that Rommel didn't understand mines is ludicrous. He was probably THE expert on landmine warfire in the Heer, if not the entire world at the time