Did he deviate? Yup. The toothbrush version wasn't the original:
"His moustache is the most instantly recognisable - and sinister - in history.
Yet, according to new research into Adolf Hitler's early life, the distinctive, toothbrush shape that adorned his scowling face was not his first preference.
Untrimmed: Adolf Hitler’s original moustache style
in 1914 and his later distinctive toothbrush shape
A previously unpublished essay by a writer who served alongside Hitler in the First World War trenches reveals that the future Führer was only obeying orders when he shaped his moustache into its tightly-clipped style. He was instructed to do so in order that it would fit under the respirator masks, introduced in response to British mustard gas attacks.
Had that order never been issued, the tyrant who brought most of Europe to its knees would be remembered as a man with a large Prussian moustache.
The prosaic explanation comes in a new biography of the writer Alexander Moritz Frey, who came to know him when both were lowly privates in a Bavarian infantry division.
In a hitherto unpublished essay, Frey, who died in 1957, wrote of his first meeting with Hitler in 1915: "A pale, tall man tumbled down into the cellar after the first shells of the daily evening attacks had begun to fall, fear and rage glowing in his eyes.
At that time he looked tall because he was so thin. A full moustache, which had to be trimmed later because of the new gas masks, covered the ugly slit of his mouth."
Stefan Ernsting, who has written the biography, unearthed Frey's essay, The Unknown Private - Personal Memories of Hitler, in archives in the provincial German town of Marbach.
Frey's account provides the first substantial challenge to historians' perceived wisdom on the subject, which has generally been that the Nazi leader was simply following the fashion of the period.
However, whatever adjustments Hitler was forced to make to fit German army gas masks did not save him from being badly gassed and temporarily blinded during a British attack in 1918."
Try the link for a picture of him in 1914 with a much larger mustache.
There have been plenty of "evil dictators" without any facial hair.