Personally, I thought the idea of the Alliance sending all the ships to the same "Sector" was kind of silly from a survival perspective, but I understand that they wanted a relatively tight conflict zone for the SP campaign.
It would actually make a lot of sense for expeditions to have gone in different directions, especially when, as is obviously the case in the FL universe, they had no master plan for assisting each other in getting established.
As to incorporating it into Disco, the one way gate/uncontrolled jump is a tired cliché but about the only thing that really let's you play in the sandbox unless the devs/admins add heretofore unknown systems and routes.
