Vierling or Herrera may not be that good on their strong platoon side. Of course, we have some reason to believe they may be that good, but Herrera has been all over the place offensively, and Vierling... very small sample size. So I think the point stands; a .750 OPS outfielder with average CF defense, if he doesn't have a serious platoon split, might arguably be our best starting CF.
I would like to see a .750 OPS or better CF (or CF platoon) with strong defense. If we had that, then I'd be inclined to prefer a better bat, with less concern for defense, in a bench outfielder/1B type. But I'm not convinced that we have that. Now, maybe Vierling will prove to be what his small sample size optimistically suggests. That would be lovely, but I wouldn't bet the farm (or the season) on that.