Their Oliver projections are a 44% difference in wRC+.
However, that was unfair, considering that it IS Oliver. Steamer has them at a 20% difference, and ZiPS at a 19% difference.
But, then again, our very own Chris Carruthers has them at a 39% difference. So, it's very reasonable to say there's between a 19% and 39%, with 44% being an unlikely but possible difference. So yes, Olerud, the differences between them ARE that big.