theres def more crews and drug organisations within the gangs in chicago its a massive market. Theres also alot of little gangs and factions made up entirley of teenagers and young guys that are running around on their own. The street level dealer is probably more typical of the low level gang member, makes money by himself with a friend as muscle. He most likely buys his drugs off an older gang member , mid level guy but i doubt they oversee what hes doing on a daily basis.

heres the link to the detroit episode. http://www.youtube.com/watch?v=P1xPPS3UjRE