I really think Sarno (And from behind the scenes, Solly D & Jimmy I) probably wanted to just do away with the Carlisi/Marcello faction & claim those rackets for themselves. The two factions had peacefully shared territory for so long, and by the early '00s, the Carlisi people had next to nothing going for them in terms of manpower & influence. So why not just get rid of their last two big dogs, Zizzo & Hatch, who were constantly trying to go against the grain?