Hmm... Anthony taking over on his own would be a bit of a stretch, but I love the idea of him hooking up with one of his cousins and going up against Vincent.

Anthony would be really smart to reach out to one of Connie's kids, which might go a bit of the way to neutralize her. If it was Anthony on his own, she'd throw her weight behind Vincent, who has way more cred even having been outside the Corleone family. At least Vincent has the street cred, while Anthony doesn't even have the law background.

I can definitely see how Mary's death, and the effect it has on Anthony's mother, driving Anthony to seek retribution from those he'd hold responsible.