In the Alter Heim A Rebbe could be the Rebbe of a town, but not really the next town because of the time to travel, so many times the sons would divide the followers that way
Not to pick on Satmar, but Kiryat Joel vs Williamsburg is a good example, they were too far away in the Alter Heim so the brothers would have just split it up and getan, but today travel between the 2 is pretty easy.
You now have the the Same Rebbe in many groups the same Rebbe in the US, Antwerp and Israel, that never would have happend as it was almost impossible for such travel