The flaw in your logic is expecting both to come out and play that well. I'm sorry but 22 year old rookies coming and hitting 30 HR's isn't that common and you're expecting it from 2 players on the same team in the same year. I'll even give you some wiggle room. Do you know how many rookies between the age of 18-23 have hit 25 or more home runs since 2000? You're talking about Mike Trout(30 2012), Wilin Rosario(28 2012), Evan Longoria(27 2008), Ryan Braun(34 2007), Chris Young(32 2007), Prince Fielder(28 2006), Mark Teixeira(26 2003), and Albert Pujols(37 2001). With the exception of Rosario and Young, you're talking about 6 yearly MVP candidates during their prime years. In those years, Trout was 2nd in MVP voting, Longoria was 11th in MVP voting, Braun was 24th, and Pujols was 4th in MVP voting. So, you're basically talking 2 rookies having border line MVP seasons.
Like I said, I think you're expecting far too much. Hell, if one of the two has a longoria type rookie season people should be thrilled.