Thomas Cranmer was a great hero of the faith, and a martyr. He was also a man who buckled under pressure at the end of life, and signed a paper recanting his biblical position. But he was also a man who courageously recanted his recantation, and was immediately hustled off to be burned. He then put his offending hand, the one that had signed his earlier denial of the truth, into the fire so that it might be the first to burn. So do not despise the coward/heroes. God uses them.
Edmund was a poisonous little beast, and so one of the things Aslan did was die for him in order to make him a king.
Good read on dealing with cowards and specifically cowards that are making amends after recognizing their cowardice. Jesus died for cowards too. Forgive them and welcome them home.