The article indicates that Pietrantonio and Desjardins might be on the same side. Not suprisingly both faced an attempt on their lives. If Suziki's group took out Montagna, it might have been a major blow to the Ontario criminals because Montagna was probably their man in Montreal.

Also, the initial killings differ from the latest ones. There were months between the kidnapping of Renda, the murder of [BadWord] and the murder of Rizzuto, and all succeeded, suggesting that these were carefully planned.

However, the latest attempts seem to be rather clumsy, considering that two out of 4 failed, and the another one almost failed (Montagna). Also, these latest attempts followed in rapid succession, indicating that there's now a war going on.

That failed mob meeting in September supports this theory.