Agree with most of that but isn't Milner the same age ? He also began his career early and the difference in fitness is monumental. Rooneys lifestyle has also taken its toll, smoker isn't he as well I think.
Milner started at 16 you're right but Rooney was ready before he was even allowed to play. Apparently when smith was here he went to see Colin Harvey while he was watching an U19 game , while there a player scored from the half way line and smith said he wanted him in his squad, colon replied you can't, he's only 14. Physically Rooney was fully developed long before he started being eligible to play and could have made his debut at 15 when he was on the bench for us against Southampton I believe