Now that they have returned Ganthet to the cold and emotionless Guardian state that the rest of them share, he brings them new wisdom from his times among those who feel. Primarily that great will does not mean lack of faults in character. He talks about Hal and Sinestro as examples to express that the Green Lantern Corps is inherently flawed. Then there are the Manhunters whose faulted programming led them to be replaced by the Green Lanterns.
So now it’s time to replace the Green Lantern Corps with “The Third Army”.