Nightmarish

Well, that is a movie that is going to give me nightmares:

Conspiracy: On January 20, 1942, 15 men gathered in a villa on the outskirts of Berlin for a clandestine meeting that would ultimately seal the fate of the European Jewish population. Ninety minutes later, the blueprint for Hitler's Final Solution was in place. Adolf Eichmann prepared 30 top-secret copies of the meeting's minutes. By the fall of the Reich, all had disappeared or been destroyed--except one...

Question: How close is Kenneth Branagh's Heydrich to the real Heydrich? How close is Colin Firth's Stuckart to the real Stuckart?