General Chat / Why is Jack Black considered a core member of the Frat Pack?

wtFF is Jack Black considered a memeber of the Frat Pack (also includes Ben Stiller, Owen Wilson, Luke Wilson, Vince Vaugn, Will Ferrell, Steve Carrell, and then has several "levels of trust/friendship" below that core, with folks like Paul Rudd and Seth Rogan and suchlike appearing on lower tiers.

I want to know why Jack Black is considered not just a memeber, but a CORE MEMBER!! According to Wikipedia's article on them, in the list of movies, Jack Black has appeared in the following Frat Pack films:

The Cable Guy (Supporting Role)
Bongwater (Supporting Cast)
Heat Vision and Jack (unaired) (Lead Role)
Orange Country (Lead Role)
Envy (Lead Role)
Anchorman (Minor Role)
Danny Roane: First Time Director (Supporting Role)
Tenacious D in the Pick of Destiny (Lead Role, Writer, Songs)
Tropic Thunder (Lead Role)
The Big Year (upcoming) (Lead Role)

at first this seems like not a bad list, but think for a moment about not just quantity but quality. The term Frat Pack was not started until the mid 2000s.
* The Cable Guy came out back in 1996, and the only other memberes were Stiller and Owen Wilson as minor roles, and Stiller directing.
* Bongwater is a forgotten film from 1997, with Luke Wilson in the lead role, and no other frat packers.
* Heat Vision and Jack was unaired.
* Orange Country came out in 2002, the only other frat packer was Stiller in a minor role, and is largely forgotten.
* Envy is the first film made with Black once the term Frat Pack was established (2004). However, it is considered horrific. I personally didn't mind it, and I think of the films so far is Black's most legimiate claim to be in the Frat Pack. Whatever.
* Anchorman is another somewhat legimate claim, as this is the film with the most frat packers, in any capacity. Only Owen Wilson was not in it, and only the clinically insane would not count him as a Frat Pack member.
* Danny Roane is largely not really a "Frat Pack" film, as the only other member was Stiller in a minor role, so Black and Stiller are not the main folks in this movie, or behind this movie. Also it is largely forgotten.
* Tenacious D is really just a Black project, the other other involved Frat Pack member was again Stiller (minor role, producer).
* Tropic Thunder is BY FUCKING FAR Jack's most legitimate claim to being in the Frat Pack, it is considerd one of their best films. I personally will never see it, as I have no desire to see the retarded get made fun of, but I can not contest that is a legimiate Frat Pack film. BUT IT IS ONE MOVIE. No one is suggesting Robert Downey Junior get made a Frat Pack Core Member (he is generally put one of the lower tiers, however). FUTHERMORE, Black was considered a main Frat Pack member LONG BEFORE Tropic Thunder came out, which baffles me.
* The Big Year is as of yet unreleased, so that hardly counts.

Now, someone like Vince Vaughn has about as many credits as Black, BUT, consider what they include: Zoolander, Old School, Wedding Crashes, all of which he is in a main role, and, more importantly, all of which are considered true "Frat Pack Classics."

Furthermore, Black's solo output (well, solo in the sense he is the only Frat Packer) includes movies like the Shool of Rock, Nacho Libre, Be Kind Rewind, Kung Fu Panda, and the non-comedic King Kong. These films are all better known and more highly liked than his Frat Pack outings.

I am not bashing Black as an actor.

tl;dr I am merely confused about why Jack Black is considered not just a frat pack close contributor or friend, but a MAIN, CORE MEMBER, when he is limited films with other frat packers, which often have poor reception, and he is better known for his not Frat Pack work. I just do not think of Black when I think of folks like Stiller, Vaugn, the Wilson brothers and Ferell, and was surprised and still am to see Black named among them so much, and considered a core member of the Frat Pack.

Why is this?

Thanks!

*SIGH* He's back.