Giving me flashbacks to the game Space Station 13. It was never "the clowns", just "The Clown". And it absolutely was a threat.
More often than not, the person who picked the singular clown role on the station (or who mugged the person who did and stole the costume), would be someone who was highly skilled with the game who wanted to get up to shenanigans.
I've watched a clown armed with nothing but two banana peels single handedly take out an entire security force, steal their gear, disappear while the station gets wrecked by a changeling, then pop back out and lure the changeling into a carefully built conveyor belt system that traps them in an inescapable loop of being knocked over forever, trapped, forced to listen to infinite bicycle horns and a farting robot made out of their own cut off butt.
The clown then used the opportunity to set the station's black hole engine loose, destroyed the end of the hall to the escape shuttle, and lubed the floor. The survivors, rushing to escape, slip, and glide out into the void. More bicycle horn honks are the last sound they hear.
That makes sense. But it gets more difficult when posses consist of more than just insane clowns. I suppose when you're talking about a posse of insane clowns, the odds of it containing sane jugglers are pretty small. But when you're talking about an insane posse of nondescript clowns, the posse must consist of at least half plus one insane clowns. The other clowns can be anything in between.
But this is assuming that a posse can only be described as insane if at least half of the posse needs to be insane to make it an insane posse.