Here's what's wrong with your logic. You look at track records, not what's happening in the first weeks of the season. Do you honestly think that Eric Chavez, Erubiel Durazo and Jason Kendall will continue to hit like they will? That's absurd. It's one thing to hope everyone has a career year (which you're pretending that I said) and another for a player to play to their ability. When someone has been playing for a number of years, it is safe to look at their track record and see what they're going to do. Here is an example so you can understand it:
Eric Chavez (Year: Batting Average, Home Runs)
2000: .277, 26
2001: .288, 32
2002: .275, 34
2003: .282, 29
2004: .276, 29 (missed 6 weeks w/broken hand after HBP)
2005: .190, 2
Now, if you look at what he's done the first few weeks you would project that he's only going to hit about 10 home runs this year, even though he's been hitting about 30 year after year. That's stupid. It's a safe bet that he'll hit at least 30 again. He's just coming into his prime and is healthy. To think that he's going to continue hitting like he is right now is absurd.
The same goes for Jason Kendall. He is a veteran, and a career .300 hitter. He's proven that he can hit, he's done it year after year, so all of a sudden he's just going to fall off and forget how to hit? Doubtful.
These guys are safe bets. Here's an example of someone who is not a safe bet.
Adrian Beltre (Year: Batting Average, Home Runs)
1999: .275, 15
2000: .290, 20
2001: .265, 13
2002: .257, 21
2003: .240, 23
2004: .334, 48
2005: .242, 2
After hitting between 13-23 home runs a year, Beltre breaks out and hits 48 on the last year of his contract. Will he do this again? Probably not. He doesn't have the track record of doing it year after year.
It is safe to look at history to make a projection unless someone is at the tail end of their career.
The heart of Oakland's lineup has already proven that they are solid hitters, and they are in a slump right now... So they have zero production from them and are only 4 games out. If you use logic and actually think then you'll understand that they will do better.
And about Mulder, his win-loss record from last year is an illusion, he had #5 starter type numbers. Like I said before, those aren't very big shoes to fill, everyone just thinks they are because he's a big name player.