One more point to note about their methodology.

It is true that they talk about discarding the weakest links, but this is just a matter of discarding the "blinking links," i.e., only retaining links that have been over the threshold $Q$ for at least 5 consecutive years going back from the present. But I don't see how this set of surviving, robust links would get reduced by increasing of other link strengths in the Pacific. If anything, I would predict that an increasing of link strengths in the Pacific would just increase the number of robust links.