Composite heroes
HOWARD MOON: The thing is, we clicked, Vince, we just clicked, you know. And that is something you can't fight, you know--chemistry. Yeah, I've got the dark, fractured, broken, paranoid sort of side to me, and he had the light, sunny, simpleton feel. Together we made sort of one whole person--together.
VINCE NOIR: But that's our angle!
--The Mighty Boosh, "The Power of the Crimp"
It's notoriously hard to analyze comedy--or rather, it's supposed to be, but I feel that's more because the people who analyze literature tend to be pretty humorless and do a really horrible job with comedy, assuming they even recognize something as comedy to begin with. In fact, one thing that drove me crazy when Seinfeld was on the air was the assumption made by just about every cultural commentator out there that the characters were created and envisioned as serious role models--you know, of course the people who wrote the show thought the world would be a better place if everyone acted like George Costanza, and of course everyone was watching the show not to laugh at George's foibles but because they wanted to be just like him.
I guess if your job is to come up with reasons to bemoan The State of Things Today, that sort of "analysis" makes sense, but not otherwise. Another aspect of comedy that is often analyzed in a really dumb way is the prevalence of buddy comedies--instead of one protagonist, you have two (or many more). The "reasons" critics often give for this is 1. everybody is secretly homosexual, or 2. men hate women. (You're wondering about female buddies in comedies? Lucy & Ethel? Bridesmaids? The Bennett sisters? Oh, silly you, those don't exist.)
When I was an undergraduate, I read the comedic novel Joseph Andrews by Henry Fielding. The full title of the book is The History of the Adventures of Joseph Andrews and of his Friend Mr. Abraham Adams--so, you know, it's a buddy comedy, and for me, it was the first buddy comedy I ever tried to analyze.
Joseph Andrews is a spoof of Pamela, with the hilarious premise being, Here is a young man trying to defend his chastity! HAHAHAHAHAHA!!! OK, fine, that's hilarious mostly by 18th-century standards. But despite the unpromising premise, Joseph Andrews turned out to be a surprisingly worthwhile novel about a young man trying to navigate the world of sexuality--think of something along the lines of American Pie or Another Gay Movie, but far less explicit.
Like the characters in those movies, Joseph Andrews is trying to channel his sexual impulses in a functional way--he's very much in love, and he does not want to sabotage that relationship. He is, however, a young man with a full complement of young-man hormones (and apparently quite the looker), so he is faced with temptations on all sides.
Helping him navigate those temptations is his buddy and parson, Abraham Adams. Whenever Joseph starts to stray, Abraham pulls him back into line. Abraham isn't perfect either--he's super-gullible. If it weren't for Joseph riding herd on him, the parson would give away his life savings to the first sharpie with a sob story he met.
You see how that works for a comedy? You're never faced with Mr. Super Perfect Guy or some boring allegorical character. ("I am Chastity!" "Hello, Chastity! I am Charity!" "Hello Charity! Let us trod upon Sinner and walk up to Heaven upon the Path of Righteousness!") In fact, you're faced with quirky people who do wacky things that you would never do.
On the other hand, you're also not faced with a situation that turns so horribly serious that it is no longer funny--Joseph doesn't destroy his hoped-for marriage, Abraham doesn't starve to death after losing all his money to a con artist. It's not a classical tragedy, where a character's flaws lead to his destruction. In a buddy comedy, a character's flaws make him go awry for a little bit, but eventually his buddy gets him back on track.