Any introverted function seems to be ranked similarly to its extraverted equivalent (such as Ti and Te), they are never separated by much.
Accordingly, the first four functions according to the usual order are not ranked first, but spaced pretty evenly throughout all eight.
Makes sense to me. A person with high Ti will often use what looks like Te, but it's still right to say they mostly use Ti. I think the usual conception/ordering of the shadow functions might be wrong.