Guderian described him as "brilliantly clever, conscientious, hard working, original and talented" but had severe doubts about his decisiveness, toughness and lack of command experience.
Guderian ga opisuje kao "briljantno inteligentna, savjesna, marljiva, inovativna i talentirana", ali već tada izražava svoje sumnje oko njegove odlučnosti, čvrstine i nedostatka zapovjednog iskustva.