I always wondered what Luca's position was and whether he was just the best and toughest soldier the Corleones had or whether he was a capo. The same with Pentangeli (i know spelled that wrong) was he Clemenza's right hand man or what because it seems like he had to wait for Paulie Gatto to get whacked and Rocco to become a capo before he moved up. I guess he would have been considered maybe a capo or underboss?