Vincent was not a wannabe, but he did desire "legitimacy" within the family (as Michael wanted "legitimacy" in the world). It is no accident that after Michael made him apologize to Zasa that he stuck around to tell Michael that he knew Zasa was angry because Michael was keeping him from rising up in the commission. He also took full advantage of Connie's desire to see him succeed Michael, and he even had the affair with the none too attrative Mary.

Basically Vincent came from nothing and becoming a real member of the Corleone family was the culmination of his mother's and his lifelong desires.

That said he didn't do such a hot job securing things at the Opera. Maybe he was on Altobello's payroll.