3rd in Command?
I am always amazed that movies (and history books) rate Heydrich as 3rd in command after Hitler and Himmler. Whilst it is certainly highly likely that Hitler was grooming him to potentially be Fuhrer one day, at the time of his assassination he was still only a 2nd tier figure. He was head of RSHA (all German security service, SD, gestapo, Kripo etc) and in overall command of the einsatzgruppen. It's highly likely Hitler made him the Reichsprotector so that he could learn how to govern (the Nazi way).
But Himmler wasn't even the 2nd person in the reich. Goering was the Reichstag president and Bormann effectively was in charge of the party. Even the vain, arrogant and incompetent Von Ribbentrop was in the top tier.
Had the war went differently and Heydrich survived he would more than likely have became a tier one figure and probably Fuhrer. But not in 1942