It IS an interesting paragraph, DC. It proves that FFC changed Fredo's character even in GF1, and of course 2.
It shows that Fredo was not so ruthless, yes, but don't you think that he was not as stupid and weak as he pictures him? Even in the scene with Moe in the book he does not look so hopeless. He is not the leader, though, and he amuses himself too much with young girls... But that's all.