We just bought a mare and a gelding that had been pasture mates for years (someone shoot me!). At the previous owner's home, they were extremely buddy sour. However, at my home, there are other horses (including the daughter's stallion, dangit) and the mare has joined up with them. The gelding is content to stay in the big lot next to the house (because the stallion picks on him unmercifully!). The buddy issues seem to have resolved themselves for now. The mare doesn't mind being pulled out of the pasture and worked with, which is a blessing, because she needs a LOT of work!