Silva is a very sleek fighter I have seen his greatest fights when he was young and at the height of his career, his movement is great its just unfortunate that he takes up boxing quite late, he can make a good career out of boxing, his win against Chavez Jr. can be considered as one of his top fight as Chavez Jr. is still young and a veteran in boxing if Silva shows up with the same stamina and skill when he fought Chavez Jr. then he has a good chance but we must not forget Silva is not young anymore and there's a saying in boxing the mind still wants it but the body cannot keep up anymore, we'll see in this fight if Silva's body can still keep up.
Same with me, though we can say that Paul is very much younger than Silva still we can say that in terms of the experience, stamina and endurance Silva will have more than Paul.
I would agree with the experience but I doubt Paul will come in second when it comes to stamina and endurance. Paul is still young so he has probably more gas in his tank if conditioned properly. We'll the truth, we don't know who will last longer until they meet in the ring.
Just like other boxer I am following like Pacman if I am not mistaken there are some younger boxer than him but because he still has the stamina and the speed he won in that particular match.
The catchweight fight of Pacman takes away the reserve tank of his opponent. Since Pacman't opponent needs to burn more weight, they are probably overexerted and already exhausted even before the fight starts, and that greatly affects the boxing performance of a fighter.