That particular cartoon is one of my dad's favorites, as he spent some time lifting mines for the 79th Camerons in Italy. He enjoyed his stint with the British Army, particularly the "stop the war for tea" at 4:00. . . . he says that the entire column would halt, everybody would pile out of the Bren carriers and fire up the tea kettle. His report was that the guys in the 79th were "perfect gentlemen" but bonny fighters just the same.
Maybe spit & polish and effectiveness are not entirely exclusive -- for folks who don't happen to be Americans, particularly in the South and West. It's not just the cowboys - the Confederate soldier in particular was well known for his, ah, negligent dress, and it wasn't all due to the failings of the CSA quartermaster department.
BTW, I don't know if you had heard that Bill Mauldin has fallen on hard times. He's very, very ill in a California nursing home, not really expected to recover fully although he is holding his own. Apparently the only thing that cheers him up is hearing from his former buddies in WWII. My dad and his buddy (who went through WWII together from basic training forward, until his buddy was wounded in France) have written him a couple of times. I also understand that the Sergeant of the Army paid him a visit carrying an honorary promotion to Top Kick (1st sergeant) and a commendatory letter from the Joint Chiefs. I'm glad the Pentagon boys appreciate him (they didn't always - but my dad and his friends sure did, and do!)
Realized after I posted that "guy" has a different meaning for you. Nobody here has ever HEARD of the Fifth of November (other than just another day in a rather rainy month), so "guy" is just the same as "fellow" or "bloke" or whatever - it's neutral not negative. (Didn't want you to think that my dad thought that!) :-D
I've never seen the movie, so I prefer the old Dudley: