Just how long had Tomar been the Green Lantern of Sector 2813? As I recall he had been one of the first Green Lanterns selected and was honored as such. (Although my "oldtimer's disease gets in the way most times...LOL) And when he perished in COIE's wasn't his ring passed on to his brother?
As for Superman I recall during the Armeggeddon fiasco that when future Clark was elected President, that the Gaurdians tried to present him with a ring because he made Earth a peaceful Utopia like planet? He eventually turned it down.