No Buscemi but the other two are also in O’ Brother Where Art Thou, and of course Buscemi was a significant character in Fargo as well as a small role in Miller’s Crossing (vastly underrated movie). In general, the Coen Brothers like to work with many of the same actors repeatedly.
Stranger
Larry Blamire used virtually the same cast (Fay Masterson, Andrew Parks, Susan McConnell, Brian Howe, Jennifer Blaire, Dan Conroy and Robert Deveau) in his tetralogy of B-movie spoofs.
Friedberg and Seltzer also had a go-to roster of actors for their parody movies: Carmen Electra, Jennifer Coolidge, Fred Willard, Jim Piddock, and Diedrich Bader, among others. (Coolidge, Willard, and Piddock appeared together in Best in Show and A Mighty Wind, mentioned upthread.)
Just to take your example as inspiration (and this is kind of cheating…), but the three Monty Python films (obviously) had quite a few actors in common, playing different roles (and different roles in the same film too). On a similar vein, what about the ‘Carry On’ films too?
It was very common in Hong Kong in the 80s and 90s. When a lot of actors seemed to put out a movie every couple of months, it happened.
Wong Kar-Wai’s Ashes of Time took so long in the editing room, that its parody The Eagle Shooting Heroes, was produced and rushed into theatres first. And it had mostly the same cast: Leslie Cheung, Brigitte Lin, Tony Leung, the other Tony Leung, Maggie Cheung, Carina Lau, Jacky Cheung.
As well, Tony Leung (no, not that one) was also in Days of Being Dumb, Bullet in the Head and A Chinese Ghost Story 2 with Jacky Cheung. Who in turn was also in Boys Are Easy with both Maggie Cheung and Brigitte Lin. Brigitte Lin was also in Chungking Express with Tony Leung and both Black Panther Warriors and Dragon Gate Inn with the other Tony Leung (who was also in Boys Are Easy, come to think of it). That same Tony Leung co-starred with Chow Yun-Fat in A Bettter Tomorrow 3, God of Gamblers Returns, and Prison on Fire.
It goes without saying that Tony Leung Kar-Fai and Tony Leung Chiu-Wai made several more movies together that I haven’t mentioned above.
Yeah, that’s cheating. 
Similarly, I thought about the Crosby-Hope-Lamour “Road” pictures, and exclude them. They’re different characters in name only.
Akiko Wakabayashi and Mie Hama both appeared in the 1965Japanese spy/comedy movie Kokusai himitsu keisatsu: Kagi no kagi , which was excerpted as the Woody Allen spoof What’s up, Tiger Lily?, and both were “Bond Girls” in You Only Live Twice (1967)
They were also both in King Kong vs. Godzilla (1963)
You need to mention the various Wes Anderson films, which often have some or all of Bill Murray, and the Wilson brothers (Owen, Luke and lesser known Andrew), including Rushmore, Bottle Rocket, and Royal Tenenbaums.
edited to add: Jason Schwartzman too
Woody Allen is another director who likes working with the same actors. A threefer per the OP: Mia Farrow, Blythe Danner, and Judy Davis appeared in both Alice and Husbands and Wives.
Bob Balaban is a regular in films by both Wes Anderson and Christopher Guest
Robert Redford, Paul Newman and Charles Dierkop. All in Butch Cassidy and the Sundance Kid as well as The Sting (is anyone else in both?).
Jean-Pierre Jeunet reused near-whole casts from one movie to the next. (Just look at the cast lists for Delicatessen, City of Lost Children, A Very Long Engagement…)
We could spin off a tangential discussion: which directors had troupes (John Ford, Wes Anderson, Woody Allen…) and who is in each?
(Speaking of Wes Anderson: this came up in conjunction with SNL’s 50th. I thought it was hilarious, especially Edward Norton’s impression of Owen Wilson.)
Ingmar Bergman’s films tend to include some combination of Liv Ullman, Max von Sydow, Ingrid Thulin, Erland Josephson, Gunnar Björnstrand, and one or more Anderssons.
(E.g.: Von Sydow, Ullman, and Josephson all appeared in Hour of the Wolf and The Passion of Anna.)
Many of these people first met because they were members of the Cambridge Footlights or the Cambridge University Amateur Dramatic Club.
that was good! I had never seen that…would definitely watch that movie
I used ChatGPT to answer my own question. These 4 have appeared together in 5 different films (including uncredited and/or cameo roles): Zoolander, Starsky & Hutch, Wedding Crashers, Anchorman. Any combination of 3 of those 4 will get anywhere from 2 to 5 hits.
How would that be possible? If all four of them are in 5 movies together, how can 3 be in two movies?
One of those AI hallucinations. 
Brings to mind What’s Your Number? — where the female lead crosses paths with Chris Evans, Anthony Mackie, and Martin Freeman, from Captain America: Civil War (or, if you prefer, Evans and Mackie and Chris Pratt, from Avengers: Infinity War and Avengers: Endgame).