The way I see it autonomy on is sims acting on instinct, without the higher cognitive functions active. Basically they're constantly drunk, drugged etc., not their real selves.
What I'd do is put them on probation. The Chief will send them on a mission or team building measure together (Manage households, yes, they won't see their families for a while, but that's what you get for dragging down the precinct's reputation). The catch here is that sims will always choose their own conversation topics, so the befriending is not guaranteed to work. Can still go either way.