What are you talking about? For a long time, we have known that besides the NKVD, in WWII Stalin formed Smersh, a military intelligence and counterintelligence directorate. Its acronym in Russian means death to spies. The two organizations did spy on one another and jockeyed for power. Stalin also had a personal bodyguard that watched top officials in both. No one in Soviet society was immune from arrest and execution. Overlapping and parallel police/security forces is not uncommon in authoritarian regimes. Saddam Hussein had the Republican Guard watch the regular army and the Special Republican Guard watch the regular guard.