What are your thoughts on the mental state of the character of Gunnery Sergeant Hartman from Full Metal Jacket

Anyone here have similar thoughts as I do?

On the movie Full Metal Jacket by Stanley Kubrick; I have often head-canoned that most Drill Sergeants (Army), Drill Instructors (Marine Corps), Military Training Instructors (Air and Space Forces), Recruit Training Company Commanders (Coast Guard) and Recruit Division Commanders (Navy) only use aggressive negative reinforcement as an attention-getter or motivational performance theater/theatre to get recruits to be able to follow orders and toughen them up for the rigors of both military life and the stresses of front line combat. That much is likely to be expected.

But the character of R. Lee Ermey's Gunnery Sergeant Hartman, even for a Drill Instructor character, was flouting many lines and regulations crossing into abuse, cruel and unusual punishments that would have have warranted him being court-martialed, landed in Fort Leavenworth, and or drummed out of the Corps on a dishonorable discharge. It is in his idolization of the murderers Charles Whitman and Lee Harvey Oswald that I believe director Kubrick intended us to see Hartman is not meant to be a hero or even antihero by any stretch. A caricature of a military machine.

In the Trope Pantheon pages for Cultural Values and Military Ranks, I've been wanting to share my own interpretations of Hartman as being genuinely a sick person with homophobia, misogyny and xenophobic racism that isn't just Socratic discourse/rhetorical performance theater to motivate the recruits of Platoon 3092 and therefore the abstracted villain of the first third of the film. My feeling is that Hartman and only he always was a psychotic, hateful Jerkass and the Marine Corps was just a convenient outlet or excuse for his wrath, pride and near-sadism.

Personally, I would like to know if this interpretation would have any merit and plausibility in Doylist (out-universe) and Watsonian (in-universe) terms with you all. mdalsted told me that and I paraphrase - It's generally a bad idea to try to apply modern morals to characters from, in this case, the era of the Vietnam War. It can lead to erasure of history, and those who fail to learn from history are doomed to repeat it. This is what Bill Maher has called out as the scourge of "presentism". But I want to know if my take of Hartman being a villain has any merit in your eyes.

It might be just me, but what would possibly make you think Hartman could in fact be one of, if not the, bad guys of the movie?