Do not rely on technical means to solve an administrative problems. Vito Corleone didn't have messenger apps, email or ERP systems, but his enterprise ran like like a clock. So should yours.
2. It was fictional.
2. There were a lot of non-fictional organizations that ran just fine without any modern means. Genghis Khan conquered a lot of countries without relying on radio for communications or satellites for reconnaissance. Using a WhatsApp-like chat apps to communicate about criminal activities is very convenient, but opens a new vector of attack against you.