Even when some sets are connected in some way across country, ultimately it's going to be limited to a fraction of members.

Just thinking about LA alone, and how fragmented the various sets are among Crips and Bloods are, how much benefits is there having some dudes cross country claiming your street other than bragging rights. I get business crime element that comes with it in some cases but even there it isn't like the entire set at home is in on it.
Federal prisons there's more mixing of gang members in different regions. So I can see that as a potential benefit.
Just my thoughts.