Have you read 'Chimpanzee Politics' by Frans de Waal?
Yes indeed. I don't know whether it's hardest to start with 2 large groups, several small groups or a batch of ill-socialised individuals. I do know that I wouldn't know where to start and I would be very worried by the task. I think it is tribute to all the keepers involved, and to the social nature of chimps, that all 3 projects succeeded.
Alan