Note the note at the bottom of this section: - "Compare VOR and ADF systems to detect possible map shifts". You cannot do a map cross-check, if the VOR or ADF is u/s or not fitted !!
The 1996 Croatia USAF CT-43 crash is what happens, when people use a (map-shifted) RNAV FMC approach, instead of the raw NDB/ADF.
Approach required two ADF's to shoot properly, and acft was not equipped with 2, and IIRC there was a certification issue as well. (Been a few years since I read that accident report).
If I can find it, I'll post a link to the public released USAF investigation.