Mine did fine. I got 2 from a friend who's DH gave her the choice of having guineas or him!
So, I got the guineas! LOL! I basically just brought them over and turned them loose. I had planned on keeping them kenneled for several days and gradually introducing them, but when I sat the kennel under the tree, my other 3 guineas came running over and making such a racket, then those 2 started in, and started trying to run through the wire, that I just opened the door, and they all took off together!
They had a few skirmishes the first couple of days, but nothing serious. My pair is super-dominate, even over the chickens, so they had to make sure the newbies understood. The newbies decided to show they were dominate over my female's adopted baby, so Mama had to make sure they knew that was not acceptable.
It sounds much more violent than it was. It mostly consisted of screeching and charging. No one actually made contact. Now, everyone is happy.
I think it is much easier to integrate guineas than chickens!
Shelly