I see the point you're making, but the engine models are not lining up exactly for me. The first thing is to assure you have the engine models correct, as per the TCDS for each engine (which will also give you the limitations, so you can compare "apples to apples". Thereafter, a review of the performance charts for each engine might point you toward an answer.
But, there is a little bit of marketing "black magic" still latent in some of these numbers....