Groups working together is fairly common. The importers handle logistics into the country. Another group handles distribution within a country. Others may han

Groups working together is fairly common. The importers handle logistics into the country. Another group handles distribution within a country. Others may handle distribution within towns/cities. They all have a mutual benefit of clear division of responsibilities in the journey - and thus will reduce the inter-group feuds from trying to branch out. The underground market can be incredibly efficient.