That's an interesting word - Assimilation. I have no idea if you're maybe trying to rather quote "integration", or if in the UK the word "assimilation" is used some other way then it is in the US, but...

Assimilation is something that the Borg does. It can be forceful and is primarily an act of the collective.

"Integration" on the other hand comes from a desire to be part of a society. It's more of a soft osmosis type effect.