Indeed an incredibly brave soldier who broke all tradition of the German élite general corps... A soldier, just a corporal who became the leader of many men... Sorry, the Germans tended to do that in WWII...
Well, he was first an enlisted man and he became a general!

Here are his respective promotions:
Gefreiter der Reserve (01 Dec 1937)
Obergefreiter der Reserve(01 June 1938)
Stabsfeldwebel der Reserve (01 Oct 1938)
Leutnant der Reserve(01 Oct 1939)
Leutnant (01 Sep 1941)
Oberleutnant (01 Sep 1941)
Hauptmann(01 Aug 1942)
Major (10 June 1943)
Oberstleutnant(01 Feb 1944)
Overstepped the rank of Oberst
Generalmajor(28 Apr 1945)
Do you know another man who reached the rank of general incredibly soon? Brigadier general Francisco Franco, of the Spanish Army at the age of 33.
