Introducing new breeders

I'll be picking up 3 1.4 groups tomorrow and was wondering about introducing them to one another. I've heard a lot of horror stories with males being killed immediately and females the same. If you have a member of an existing breeding group die how do you go about replacing them?

I only have one colony of ASFs. I know they're supposed to show aggressive behavior if introduced to others.

I'd suggest maybe rubbing some vanilla on their bums so they all smell the same. Although I'd keep a close eye on them incase they fight.

I would do the vanilla thing, but I usually stick their noses in it.