Not well I don't think, especially if there are moderate climbs, where the smaller 38 tooth crank on the Shred will be easier to tackle inclines. Also, the Rook has commuter tires (vs true mtb tires) that run too high air pressure for trail use and along with that the bars are set too high for trail use, especially going down hill.
Really, the Shred is not all that uncomfortable compared to a commuter ebike. In other words, I'd rather have a Shred for commuting than have a Rook that will see any trail riding.