Major reason Jeter has even been able to play in October is because of his teammates. While a great player he has done far less to help the Yankees reach the postseason than most people think, especially on the defensive side. And even once he reaches the postseason, by just looking at his stats, it appears that he is the same player April through September as he is in October
If people really argue Dimaggio as best player ever, he his vastly overrated. An All-Time great, but easy to see him behind Mays and Mantle at the same position and Williams in the same generation. But I don't think that goes on too much
Mattingly was easily better than Joyner and Olerud. Means absolutely nothing for this purpose. It would be like saying Jose Canseco was better than Raul Mondesi , therefore Canseco cannot be overrated. No one thinks Wally Joyner and Don Mattingly were equals. As far as 162 game averages, Hernandez started his career at a younger age and ended at a later age. Throw away those seasons and the RBI and runs scored per 162 games are pretty close. Mattingly has a nice edge in extra base hits and slugging percentage, Henandez has an even bigger edge in singles, walks and on-base percentage
Fielding percentage is only a fraction of defensive value. If people fail to realize that, than that is a good way to find overrated and underrated players. For a first baseman, taking away hits, starting double plays, turning foul balls into outs and saving errors from other infielders are all important as well. While Mattingly was best in the league, Hernandez was perhaps best of all-time
This is not to say Hernandez was superior to Mattingly, only that if they are not rated as at least close, than whoever is rated as far superior is most certainly overrated
Not sure about Lynn. Won an MVP in 75, by 79 he was even better. After that he was hurt every year, but still averaged 120 games a year. A good player can still do a lot to help a team playing 120 games a year. Jim Rice only played a few more games over his career and made the Hall-of-Fame while Lynn has been mostly forgotten despite the huge difference in defensive ability and playing so many more games outside of the best hitters park in the league