Junkie Days you could argue the same of cocaine and crack cocaine, to an extent atleast, but they are not marketed and sold in the very specific way that ECP #4. I just find the whole scene really interesting due to its uniqueness and also my general fascination with heroin/opioid culture.
In the city I live, Melbourne Australia, there are maybe a handful of areas or just under that could be considered open air drug markets, not as blatant as I am lead to believe ones in the US are and ones in Europe I have experienced but they are definitely there. The drug dealing in these areas tends to be controlled by Asian gangs, the same people who I am lead to believe and also logically assume control a lot of heroin importations, I would be very surprised if there were not kingins buying large quantities of heroin here and paying "soldiers", as you put it, to go out on the corner and slang for them, the difference is that here the heroin is not marketed in stamp bags, and it is sold by weight rather than number of bags. I can go to a "soldier" on the corner, who is probably working for somebody else, and he will still have at the very least .1 and .2 balloons and possibly half grams. I would say that here territory probably is less specific, and there probably is more freelance dealing as you do see plenty of white junkies flogging gear as well (as a rule don't buy off them lol) but I dunno, the differences and nuances of it in different geographies just interest me.
Take the West Coast of the US for example, you could say everything you just did about the way heroin works on the east but the scene is totally different. As I understand Mexicans generally control the trade and they employ delivery dealers who have a phone people call or text and these lower level peddles drive around and serve the customers while the kingpin rakes in massive profits, however, the black tar heroin they are selling can be bought in various weighted quantities as opposed to a number of set weight bags, and it is also never really branded as far as I am aware.