That is true for the sampling of each on the Trans America. FWIW, I wouldn't assume it to be true for riding or even crossing the two ranges in general. There are plenty of crazy hard climbs out west and probably easier ways across the Appalachians. Reportedly the Eastern Express is MUCH easier and looking at it I think that would be true. Also there is some insanely hard stuff out West I found that out when I rode the lower half of the Siera Cascades Route.

Many places in the East the roads were build with no or at least not much grading. Out west many of the roads were built later with more effort at grading and routing. The TA benefits from that. Not everywhere out there does.