It wasn’t the slapping incident and such that concerned my grandfather, but rather that he led from the rear and rode around in staff cars and ate fancy dinners. He thinks as a strategist he was effective, but the heroic vision of him was completely overblown. Just an opinion from a man who fought under him.
I used to minimize the slapping incident, but have revised my thinking as I've gotten older. That kind of thing may have been fine for the Prussian or Russian armies, but the U.S. Army tradition is more respect for the men by their officers. If a soldier needed to be set straight, the NCO's could deal with that, but an officer, especially a General, should not.
In the specific situation Patton confronted, he could simply have ordered the docs to segregate the "battle fatigue" case away from the wounded men. Losing his temper was uncalled for and Ike was justifiably p.o.'d about it, IMHO.