If my memory serves me right,
whatever Michael did were to other Mafia people [kill or be killed]
On screen, we have the dead woman with Senator Geary and the woman who's machine-gunned with Cuneo.
It has to be taken as a given that nearly everything these families are doing are being done to civilians. That's where the money comes into the system, and one way or another it's coming in by violence or threat of violence. The occasional fighting among the families is just squabbling over who gets what piece of that pie.
