I do not think they compare well at all, because I believe that those two characters stand in sharp contrast to each other. Holden is a disaffected and jaded teenager. He's unhappy with just about everyone, especially adults. He believes that they, and most of the world, are phonies. I feel that Holden complains about anything and everything, which wouldn't be so bad (I guess), if he was willing to do something about it. Even when he decides to do something, he talks himself out it soon after. He does that when standing in the phone booth trying to decide who to call. He does it when he decides to run away with his sister and then decides against it. Holden is a bit of a loner, despite his inner desire to be a part of a something, anything.
Ralph on the other hand is calm and collected through most of the novel. He's a logical thinker and is generally well liked. Ralph is a leader as well, as evidenced by him being voted chief. Once chief, Ralph is placed in a decision making role. Holden would not have done well with this, but Ralph makes intelligent decisions based on what is best for the most number of group members. I feel that Holden would have chosen what is best for himself (like Jack). I think a key difference between Holden and Ralph is a result of their lot in life. Ralph is forced to grow up very rapidly and become a leader and act like a man. Holden does everything he can to avoid growing up and becoming a phony.