Assimilation is a reward, but frightening.
Have you taken a dog or a cat to a vet?
They panic and they fight.
Even though it's for their own good to get some shots or some thing removed or stitched up, but they're going to fight, because some asshole is coming at them with a needle.
So you dope them.
And deal with the fallout.
It's amazing how quickly an animal can forgive you after you castrate them.
Assimilation is not a punishment, it's a reward for the exceptional.