There's always been lots of discussion about families merging. It's an interesting thought, after all legit corporations do it all the time, but it's really not possible when it comes to the mob. For any number of reasons.

For a smaller family, a good example of what to do would be the Outfit in Chicago. It downsized it's organization and streamlined it's operations so it is less visible and presents less of a target for law enforcement. They're not trying to run everything in the city anymore, which they can't anyway. They have a smaller core that can still profit from their time-tested staples of sports betting, video poker, loansharking, some legit businesses, etc. Keep the murders to an absolute minimum. And try to avoid violence altogether if possible. For instance, it's been said that the Outfit will just cut off a bettor for not paying rather than rough him up.