There's one thing you seem to neglect or not really understand,especially with the bolded part. Calabrese or Calabrian in Montreal doesn't always means 'Ndrangheta. I don't know if you know that or not, and that's a common misconception other forum members have made when reading articles like that. There IS a Calabrian branch of the Montreal Mafia. Francesco Arcadi is considered to be a part of that Calabrian branch. And Calabrians have been a part of the Montreal Mob since it's inception. Its just like the Controni days, which I mentioned on here before, when Cotroni and Violi ran things, the Calabrese was the power in the Montreal Mob, and it had little to do with Ontario or Toronto 'Ndrangheta.
When Violi died and Cotroni stepped back, the Sicilians (The Rizzutos and their brethren) were the power. It was suspected with the threat on Leonardo & Stefanos arrest and their incarceration, that Arcadi, Del Balso & Giordano were behind the threat, they were due to be released and reportedly wanted their leadership positions back. Perhaps thats what Costa meant when he said the Calabrians were running things. And I'm inclined to believe it was, when you look at the arrest of Girolamo.
According to Project MAGOT & MASTIF, the threats on Desjardins life, were coming from Mom Boucher and Gregory Wooley, not Calabrians. I already mentioned whom I suspect to be behind those of Leonardo & Stefano. And with Arcadi & Del Balso back in prison and Giordano dead, that isnt to say, the Rizzutos or Sicilians are back in power, but that there may be more of a counsel leadership, who simply feel more comfortable with Leonardo & Stefano keeping their positions, or the counsel setting, than seeing Arcadi and his group take control.