There are a few times when this is done with a heavy hand: the portrayals of JFK and Johnson are particularly brutal. In fact, to hammer the point home regarding the oafishness of Johnson, they had a scene where he's insulting the queen's invitation while he's actively peeing in a public restroom. In a different scene, Neil Armstrong, Buzz Aldrin, and Michael Collins (the Apollo 11 astronauts) are shown as being relatively devoid of imagination and a little uncouth during Prince Phillip's interview with them. While these portrayals lacked historical accuracy, they served well in building the overarching ideas of the episodes that they were in.
The one that I had the most difficulty with was Edward VIII who received a prominent place in a number of episodes, particularly in season three. He was the former king who abdicated so he could marry a divorced woman, and thus put his brother, George VI, and consequently Elizabeth II on the throne. Time and again, they refer to how brilliant, how individualistic, and how wronged he was. Conveniently for the story, they almost entirely ignore the fact that he was a Nazi sympathizer who had even gone out on a vacation with Hitler. In recent years, more details about his possible espionage for Germany have been coming to light, having previously been kept under close guard by the royal family. Although it is better for the theme of the third season, especially in humanizing the young Charles, it also compelled me to yell at the TV a few times.
Oh well, I suppose that history itself is an imperfect lens for the Truth behind the events of the past.