The Four Kingpins of the Wire

Stringer wanted to be a businessman. Prop Joe, at heart, was a hustler, not a drug dealer. Prop Joe just wanted to get over on you, and drugs just happened to be the way to do it. Avon almost had too MUCH swagger. He was like Michael Jordan without the athletic ability, so he competed elsewhere. Avon also had a critical weakness, which is that he cared about family and people too much.  Remember, if Avon wasn't so bothered by D'Angelo's murder, the tension between him and Stringer never gets that bad, they never betray each other, and they either co-opt or destroy Marlo.  Stringer has the co-option underway with that scene in the row home. 

Marlo? Man, Marlo was about nothing but killing and maintaining his rep.  Please note that I offer this observation not as a criticism of Marlo. Marlo had absolutely nothing else in his life other than the Game, which probably is why he was arguably its best player. He doesn't get too concerned with profit maximization, hustling the other guy, or family. In time, if he stayed in the Game long enough, inevitably he would have gotten sloppy or bored and slipped just enough for some other kid to jump up and take the crown.  I assume Avon and Stringer were a lot like Marlo when they were coming up.  

But that time hadn't come yet.  Marlo was nothing but pure, unadulterated hunger. He was a great follow up to Avon and Stringer because he's NOT cool and he doesn't have much game (as witnessed by how awkward he is with the ladies). All he has is the willingness to do absolutely anything to protect his sh!t. In the end, Marlo best understands the code of the streets: you have to do anything to survive, and you must throw away anything that gets in the way without a moment's hesitation, like some nightmare version of Buddhism.