Got it.. Its actually really easy. Corwin is effectively discussing the achievements of the Generations of the family what they did/didn't do what they caused to happen, etc. Since in the original book, "Hand of Oberon", Corwin is unaware of Merlin and only knows of Martin, Random's Son, he's just speculating as to what any children, assuming that any of his generation have any, could/would do/achieve.
Most Amber campaigns have the Player Characters as the Children of Corwin's generation, i.e Oberons Grand Children. What happens and what they, the PCs as Oberon's grandchildren is then down to both them and what the GM has in the way of plot(s).