The opening scene to The Dark Knight (2008) is the most recent clown gang I can think of.
Akira is the classic I measure all others against.
Akira’s Joker (ジョーカー) has a great upside down mouth in his early appearances.
The Warriors (1979) had two gangs that used face paint. The Hi-Hats were basically mimes.
The Baseball Furies, we’re a nice mash-up of New York Yankees and clown makeup.
Here’s the Furies in action.
The asymmetrical eye decoration of one of the Furies members is reminiscent of another face – young Alex from A Clockwork Orange (1971).
Here’s a gang fight from that film.
If you’re seeking inspiration for face make-up for a clown gang of your own, all clowns registered with Clowns International produce a painted egg to register their unique face painting – seems like a joke but isn’t :)