I specifically mean films of the same genre and tone that share much of the same cast and/or crew, but which aren't sequels and have the returning cast members playing different characters. The two pairs that come to mind for me are:
-
A Fish Called Wanda and Fierce Creatures—both are comedies featuring John Cleese, Michael Palin, Kevin Kline, Jamie Lee Curtis, Maria Aitken and Cynthia Cleese; both were written by John Cleese; they share a fair bit of their crews; and Fierce Creatures even directly references Wanda a couple times.
-
Lock, Stock and Two Smoking Barrels and Snatch—both are London-set gangster films featuring Jason Statham, Vinnie Jones, Jason Flemyng and Alan Ford; both were written and directed by Guy Ritchie, and produced by Matthew Vaughn; and they too share a fair bit of their crews.
TV Tropes does have a spiritual successor page, but it mostly includes films based on or very similar to earlier films, in addition to films that share much of their casts.
Onepunchmanworkout t1_j9kyugq wrote
Shaun of the Dead and Hot Fuzz
Edit: Giving it some thought, I've got a few.
Super Troopers and Beerfest
Waiting and Accepted
Avatar TLA and The Dragon Prince (Boomerang? 😆)
Goodfellas and Blow
Alright last one, how could I forget the DMXECU? Cradle 2 the Grave, Romeo Must Die and Exit Wounds