It would be a bad idea for them to consolidate, reason being, it would make the FBI's job easier to keep tabs on them. Just as the task forces for the Bonanno's and Colombo's have consolidated because the crews have become so small. It would make more sense for them to spread out, or make it seem so to confuse law enforcement a little, giving the illusion that there are more families operating. If law enforcement thought that there were 10 crime families in NYC, then that would throw them off, kind of like a shuffle if it makes sense. Then they wouldn't know who belongs to what group (unless someone rats) and if they can't pin them to a certain group, then RICO is harder to pin on them.