After a few years of being King of Narnia, Edmund found that he had mostly broken himself of the habit of wishing he were Peter when things got difficult. After all, he'd become close to his brother's equal in war and, it was often said, his brother's better when it came to diplomacy. But, awkwardly comforting Susan as they realised they were as good as trapped in Tashban, he wished he was Peter. Because, in the end, Peter was the oldest. It didn't make him stronger or better or smarter, but when times were tough it was he whom they looked to as their leader. Edmund could have been perfection personified and at that moment Peter would still have been able to do a better job of reassuring Susan than him. Adult or not, he was still Susan's younger brother and no amount of titles, victories or experience could change that. Edmund would get them out of Tashban and woe betide any who tried to interfere with that and Susan didn't doubt him but she also was too grown up, too proud, to lean on him. Edmund would have gladly fought giants if it would've brought Peter to reassure Susan.