Kurganskaya is the brigade that I know as most fucked up till the core. They didn't pay their own men money, the leaders just kept it for themselves. Others were given just money to buy food and to pay for their apartment. They made one guy to kill his best friend, as he hadn't killed anyone. That's why the group fell apart right from the start.
I also read there later was a big confusion about who did what: some crimes of the Butorin's Orekhovskaya were attributed to the Kurganskaya etc. There is also that Sergei "Sylvester" Timofeev story, nobody knows who killed him, if it was Butorin, the Kurganskaya, or did he fake his death.
Anyway, you are right, those groups were really out of control and played dirty even by the underworld standards. There is also Dmitriy Belkin, the leader of the "Odinzovskaya" part of the organization, who is still on trial and is mostly famous for ordering the 1998 murder of Yuriy Kerez, a law enforcement official who was the first one to open an investigation using the article n.210 (organization of the criminal association - something like the American RICO), that is usually very hard to prove.