I think I read that book Panzer Commander. I think he said about Normandy was they probably could have won the battle in the first few days but they couldn’t get armor up to the beach area. I think he said his panzer brigade suffered 40% casualties before even making direct contact with the enemy.
It’s been a while since I’ve read it, but that’s about what I recall.
I got a kick out of his friendship with John Howard, who he fought in Normandy. He’d go to the D-Day events in later years, but he had to pretend to be something other than a German officer; the French would get upset about him being there.