salvatore scoppa saw giordano and rocco sollecito as threats to his own life.
scoppa knew it was only a matter of time before stefano sollecito got out of prison on bail and wanted to weaken his position by murdering any leadership left on the street. according to andrew scoppa stefano was intent on murdering both scoppa brothers before his arrest and imprisonment in 2015.
rocco sollecito and giordano and then the murder of vincenzo spagnolo which as it turns out was a somewhat botched hit. the intent was to kill nicola spagnolo not the father. it turns out vincenzo was not a leader in current admin for the rizzuto/sollecito faction. but all 3 plus the falduto bros make 5 murders linked direct to salvatore scoppa and his crew.

now as far as massari becoming capo we can right off as a translation issue. massari was not going to become a capo i dont even know if MTL mafia uses this term. massari would have become more like a soldier working under scoppa. regardless its a mute point as he most likely will spend the rest of his life in jail.

the cut throat nature of the mafia in MTL is more surprising. sollecito trying to turn the 2 scoppa bros against each other. mirarchi trying to play all sides. mirarchis play looks to have worked as he is still living....for now.