An interesting way to do this would be to follow the Group's interactions with local organized crime, who would probably chafe at the idea of newcomers biting at their profits. The Direships have intimate ties with local organized crime, and there's the Ilium Mob in Eluvatar; I haven't thought on Myrorian organized crime much but I imagine it's violently hostile to foreigners and in bed with the Houses.
Admittedly I haven't thought much on what's illegal in Myroria so much as what's legal; that being said, I imagine in the modern era there would be money to be had in underground gambling, away from police interference, and the sale of hard drugs. Marijuana and Zuavka would almost surely be legal; but the latter would be tightly taxed and controlled. If someone was stubborn enough, I think they could make money off that. I imagine, though, that Ozian organized crime tightly controls the distribution of underground Zuavka in Myroria.
Extortion rings are a good way for new mafias to get started anywhere, so long as they have the manpower to hold their ground when neighboring mobs come to exact revenge. The Ilium Mob probably modestly increases in its fortunes after the election of Peté Tar-Ilium, Baron of Ilium and someone with rumored, though unsubstantiated, ties to organized crime.
Realistically, I see the Group fighting hard for success in Myrorian cities, and gaining it, but finding it very hard to expand their network into the rural areas, besides maybe methamphetamine trafficking. I'm very open to that changing though, so long as the story is good. If the Group becomes a big enough threat to public safety - whether it be through drug trafficking, human trafficking, or widespread murder - the government will likely direct its anger towards the Bustian government, which it would likely see as enabling the Group by its noninterference.