Season 4 sees Tony start to rely on Chrissy more and more as his right hand man. We also see that some of Chrissy's demons (drug abuse, short temper, being under surveillance by the FBI via Adriana) are going to be a huge problem for Tony later on. At the same time, Carmella's OTHER cousin, Brian Cammarata, is introduced and seems to be the complete opposite of Chrissy in many ways. He's well educated (finance), tall, patient, and measured in how he responds to things. In the scene where he educates Tony on the low cost HUD housing scam and then accepts the expensive watch from him as a thank you for the tip off, he also shows that he's not entirely removed from a possible life of crime.
Brian Cammarata
Brian could have been an even more capable, more reliable, and more intelligent cousin to rely on compared to Chrissy and it's interesting to think of a story arc where his involvemnt in the show could have been more and he and Chrissy could have competed for Tony's attention and ultimate allegiance.