Helium,
I don't know anyone who argues that you can't win with 3s. If you go back to the posters above, everyone agrees that you can definitively win with 3s.
4s is stretching a bit, but as far as I can see, you stayed away from 4s except at ss, lf, and 1b. Lf and 1b are the least important defensive positions, so you can cheat a bit. And by choosing Cedeno (ss-4e10), you kinda have the equivalent of a ss-3 with high error.
Moreover, considering that you have put emphasized on on-base and pitching (for a petco team), it seems to me that you replicated the good ol' Stratological orthodox way to win a championship!!!
Besides, Petco is the best stadium to use a very bad defensive ss.
So, with the exception of Cedeno at ss, this looks like a pretty conventional Petco team to me!! :P
That said, I still believe that you should go for defense instead of offense when deciding to which player will bat 9th in the line-up.